4/12 This $57 portable oscilloscope has a really cool feature (ZEEWEII DSO1511G review)

well hello everyone and welcome back to Adrian's digital basement on today's video we're going to do another Commodore 64 repair but I'm going to be doing it not with my normal bench oscilloscope but another one of these inexpensive oscilloscopes from AliExpress this one is called the z-way dso1511g and I paid a total of 57 for this as you can tell by the little case here it's a little portable thing but it has some interesting tricks up its sleeve which might make it an interesting choice if you're looking for one of these small Scopes so without further Ado let's get right to it foreign [Music] before we get started I just want to mention that as usual with my repair slash scope review videos I'm going to do the scope review first but if you want to skip ahead and just look at the Commodore 64 review click the link in the description below the time link to jump to that I will be using this scope to do the repair but before we dig into that I just want to see how this thing works well you know I might not be using it for the repair if it's kind of useless alright so the z-way little portable scope let's pop this out of the little carrying case it came with which is kind of nifty it's a got a rubbery coating there it is I haven't actually done anything with this other than take it out and give it a quick charge so it was fully charged for this video I have the zif64 which of course is in this vic-20 case hooked up to my PC capture device just to make sure that all of my capture stuff is working I don't want to go and try to troubleshoot a computer to have my capture system be the problem which is tricky me and thinking that the machine's not working let me move this 64 out of the way and let's take a look at this little scope here so I've had this go for a little while and I paid 57 total including shipping but the funny thing is if we look here there it shows 57.99 is the price but then there it shows 114.80 is the price and I don't know what's going on here both of these have that higher price so I'm not sure if there's like a shortage right now or something else is going on but it is odd that 57.99 is literally on the picture of the device so I'm assuming that by the time you watch this video perhaps it'll be back to that price or maybe we have to use a different seller now you see some specs on the screenshot there Let's ignore those because I'm not so sure about the validity of those as I had mentioned the carrying case feels decently nice and it's already getting a little scuffed up or whatever that was not like it when I got it so oh well so here's the scope and it's really really little there it is and let's just compare it to a Commodore 64 cartridge you can see that they're basically the same size although thickness wise it is thicker now it is in a little uh rubber bumper case here in which we can pop off if we so desire it's a typical silicone case so you know grippy but soft so probably will get dirty but because it's silicone it should be cleanable so let's look at what else is inside here we have an oscilloscope probe and it claims 100 megahertz at times 10 or times one um I doubt that it's got probe compensation so that's kind of nice and I think it was on the AliExpress listing that it listed this thing as a 120 megahertz bandwidth yeah I'm sure on the actual scope we have the single inputs just one channel we have a frequency generator for outputs good for probe compensation it is adjustable I think it's just a square wave it's not an arbitrary generator on the bottom USB type-c for charging that's nice there's a charging LED spot there and there is a 3.5 millimeter Jack which we'll get to in just a second also included here is this cable and yes what this is is this plugs into the 3.5 Jack there and this actually has video outputs as in ntsc video output so this little screen here which is quite small obviously if we go back to the cartridge there as a comparison I will be able to actually capture the video output I'm assuming on the Retro tank so we can actually see what I'm doing with this little scope that's a that's a different change from the normal hand Tech or whatever that I've shown on the channel before that thing has no ability for any video output all right we also have um this I don't know what this is I'll zoom up there uh cobal and it's just in Chinese and kind of wondering if this is like a free gift or something that was included with this um okay it's sticky is this one of those things you put on the back of your phone so you can like yes I think that's exactly what this is I wonder what these little oh no these aren't drill bits these go in here they're like tiny little jacks so I guess you can make a cable for yourself if you want they're like little mini banana Jacks like that okay and then this is for putting on the back so let's uh let's check that out so I guess you're supposed to like stick this on here like with an adhesive and then it can stick through the back you know what that actually seems kind of neat it's not stuck on yet because it will act as a little bit of a tilting bail almost so I'm gonna I'm gonna stick this on that's uh it's kind of cool yeah it tilts it up okay I like that I'll just use a little bit of alcohol here to clean under here get my fingerprints off of there or oil or whatever I'll just peel this off so we get the adhesive this thing will probably never come off and how do I do this there we go oh it actually turns as well okay yeah I like it I'm assuming this blue label here comes off which has writing on it does all right there it is it's a little tilting Bale indeed so you can actually uh adjust the angle that this thing goes by just turning this around so it's like more tilted there and uh there it stands up pretty well yeah okay cute that's pretty cool all right back to the unboxing so to speak Let's uh let's take a gander at the manual which I'm sure is not written in the best English there it is the DSO one five one oneg handheld oscilloscope user manual all right there's a section here on probe compensation it just tells you how to do it that's nice it says here that in One X the probe is only five megahertz which is pretty typical it says if measuring more than 80 volts Peak to Peak make sure you use the 10x setting which is kind of a given that's actually pretty surprising if the input on this thing can withstand 80 volts Peak to Peak or even 50 volts Peak to Peak on 1X that's pretty surprising looks like you can save screenshots and then review the images all right here's the signal generator it says it's actually good for a sine wave of 2 megahertz and other waves also 2 megahertz and then here's a section on the video output you have to go into the menu go to set and then long press Run Stop to enable video output disable if executed again so okay pretty simple I didn't realize that the USBC connector actually is data as well so you can copy the screenshots onto your computer under triggering here it looks like it does rising falling Edge triggering and that's probably it it does seem to support roll mode which is a nice feature for such a cheap little scope looks like it has Auto calibration and a fast Fourier transform functions built in and then here are the specs uh 120 megahertz bandwidth sampling rate 500 Mega samples per second these are extremely unbelievable numbers here 128 kilobit sample depth so that's that's not very deep but I mean for something that's 56 bucks I guess it says here Max voltage is 40 volts Peak to Peak on 1X which is what it said earlier in the manual that's 80 volts there AC that is we'll take a look to see if this thing supports 100x probes and if it does then theoretically it would actually be good for up to 4 000 volts I mean not really recommended with something like this but if you're testing that kind of voltage and you're not touching it while you're doing it might be okay let's use this little probe that they give us the supposed 100 megahertz probe I don't know we shouldn't need to connect that but let's anyways and we'll do the probe compensation first all right hopefully I'm not going to get glare we'll plug this into the Retro taking a second so we can take a look at the output or input that is oh hey it's got a little beeper there it is so boot it up very quickly as you saw just like a couple seconds holding down Run Stop brought the generator up all right so we are looking for a one kilohertz Square wave how do I get to square see that changes that I hold down Run Stop nope as we can see there's this signal how do I get to it let's see pretty responsive okay that moves the buffer around we're looking around the capture buffer and then we have volts and millivals I'm assuming volts increases it there it is oh it's triggering nice I think I have the probe in 10x mode so let's go in the menu and look for the probe there it is look probe 1X 10x or 100x so it does support 100x okay that's pretty cool all right let me stop myself here let's hook up the video capture to this thing and get the video output so you can see it a little more clearly than me just recording the screen here all right so it's outputting composite video right now but it just says z-way which I guess is the brand name so it told us to go into the menu and we go to set and then we hold down run stop and that should switch on the video output hey there it is look at that okay that's pretty cool actually it's not super high resolution but I'm pretty shocked for something that's 56 dollars I mean it's updating quickly it's not terrible ah wow I'm I'm kind of shocked okay so the user interface a little strange you hit menu and to change tabs you push up and down and that changes through the tabs and then to move through the items in the tabs you push left and right you see how that box around the coupling around the probe box is changing and then I think what we do is when we're on here we must push okay okay and that switches it it's a little unusual it'd be nice if you use left and right to go through the tabs and if you were on the tab you want to push down and then you could select through all the items that were in there and then you just go back up to the tab to then move left and right it's a bit unusual that way but I guess you can get used to this all right so the first tab is channel one there's only one channel on here so that's pretty simple here's the measurement Tab and we can already see it's measuring frequency and Peak to Peak and mean that's what we have at the bottom here and I'm assuming we can only get three at a time oops that exited out that was my fault push okay oh no you can actually have more stuff well that's pretty neat effectively just go to all turns them all on and turns okay well all actually doesn't turn them all off you have to manually deselect them I'm going to leave it like this frequency Peak to Peak and Max that's pretty much typically what I use the most so now we're going to switch the next tab there we have the trigger mode we have Auto and normal guess there's no single shot so that's that's a bit of a limitation okay it actually does say it has a single shot mode so it's I guess somewhere else in here we'll find that in a second all right so talking about these trigger modes Auto is just running all the time normal means it's only going to show waveform while it's actually triggering which means as soon as the trigger stops then the waveform update stops that's a useful mode depending on the situation we have rise and fall trigger types and then we can do auto or manual trigger level I'm going to set that to manual because I just don't like the idea of it changing it on its own I guess moving on we have some persistence here let's turn on some persistence this is usually kind of fake and like if I unplug the probe here yeah so it sort of Fades away that's kind of interesting you can't see what's doing in the background right let's go to the menu there look at that so that type of persistence can be useful if you have like a little glitch and if this thing actually picks the glitch up then it will stay there and I think if we go back to the menu there's a Infinity setting which just means it will never actually go away that's where you can set up also the roll mode so that's kind of nice and then the brightness which is already set to Max and to be honest the screen is completely readable and no problems um with the brightness and the viewing angle is quite good I'm looking at it at extreme angles so it's still visible on the camera and it looks completely good it's not washed out or anything all right here we are on the aux tab so there's the calibration stuff remove probe first I won't even run that then we have some fft stuff so let's uh music okay let's turn that on oh it's actually going to be doing like level bars okay that's kind of cool the fft on this is basically going to do a spectrum analysis you can see it's kind of running kind of slow but that's that's you know that's typical and then here we have the last tab we have auto shutdown on our office currently off we have sound on or off and then the language so yeah now notice there was nothing about single shot anywhere well I remember in here I think there's a button here this power button says X key and we hold that down no that turns it off we push it oh there we go okay so that pops up another menu and then we have single so I'm going to turn that on okay and you see up in the top corner there it says wait now it should single shot as soon as I just touch the probe here there it is so we get a little bit of a capture there and then it says stop so that works that's that's kind of cool it's weird that that's not in the trigger menu but I guess they wanted it to be quickly accessible hence this like X key thing here now let's see if we can click on this again to go back to the normal mode nope that just did another single shot and let's just do it again there it is there's the single shot now I was going to demonstrate scrolling through the waveform that it captured and it didn't really capture very much it like captured one screen full which is not very good at all okay now how do we get this thing back to normal mode oh we just hit run stop and then now it's back in typical mode cool all right so you see a little arrow on the right side just above the the yellow line that's the trigger point and the interesting thing is when I touch this it sort of runs without being triggered for a little while and then it triggers so I'm not I'm not 100 sure what the deal is with that it shouldn't be that slow but it's possible this thing is using a software trigger I'm not totally sure all right so there we go so now it's in roll mode it went into roll mode automatically but this might give you the idea that we're looking at an incredibly slow waveform we're not this is just aliasing so let's see if we push Auto if it gets out of this okay yeah it did cool let me try to change this waveform to a square wave let's bring up the frequency generator I think we yeah run stop I looked in the manual here and you use these millivolt and volts button here to switch the waveform okay we have noise we have something we have the top half of a sine wavel it's almost like a rectified sine wave we have a sine wave that has the bottom part chopped off so that would be like as if you put it through a diode we have a Sawtooth wave triangle wave uh there's the square wave and back to sine wave Okay cool so let me try to do the probe compensation here I have a little tool it's a bit hard to turn the adjustment you just need a very small flat blade but uh yeah that looks good enough I mean this thing is not super accurate so like what are you gonna expect out of it uh well just for fun let's switch it to one megahertz let's switch it to two megahertz let's Max this thing out okay it looks like we got some serious aliasing going on let's try the auto button here all right there we go so we're looking at two megahertz uh signal there and it's it's triggering properly it's a lot better than like that software-based USB hand Tech which barely triggers properly so okay so I have to say I'm actually pleasantly surprised by this scope at the price this thing is and the fact that it has video output I'm pretty amazed actually uh it seems to work pretty well at least off its internal signal generator so I think the real test now is let's grab this broken 64. I was going to start with the working one but let's just go right to the broken one and let's start looking at signals and let's see if I can get to the bottom of what's wrong with this thing with this little oscilloscope all right so here we are so this is one of the broken machines that I've been working on like as part of this repairathon I know it's been a few months now uh the sticker on here says number four but this is actually machine number five which has a black screen with a white line so that means that the Vic is actually generating some output what happened to number four you ask well Roman who runs the channel epictronics and sorry I put a space there Roman he actually was visiting the Pacific Northwest and asked me if he could come by just to meet me and I said yeah of course I was I was around that day so he came down and while he was here I asked if he had any ntsc Commodore 64s because he lives in Europe and he didn't so we went through the pile of 64s that I had here to be repaired and he grabbed a couple of them so he's going to have repairs on his channel I'll link to his channel down below I don't know when he's gonna do the repairs but he will have repairs and uh yeah I think it would be kind of cool to for him to have some ntsc 64s and um you know repairs on other channels so that's what happened to the fourth machine and there is another one we picked I don't remember which one it was randomly we took it out of the stack I think there's up to 13 or 12 machines there that are bad so yes okay let's uh crack this open it is not unscrewed oh look how nice the bottom looks and the top is very yellowed a sticker here has some kind of odd mottled appearance not sure what that's all about uh there appears to be one screw that is just spinning freely and the other two are already missing which implies that the standoff is broken oh there we go and I'm gonna say that someone has probably been in this thing before judging by the fact that that has been ripped off and there it is the broken machine it is our familiar friend the 25407 motherboard layout and I'm noticing there is not a single chip in a socket that's pretty ridiculous the pla is often not in a socket but the Sid Sid's almost always in the socket this is a rare thing I've had a couple come through before that were socket list as well so it's not unheard of but if you're a novice and you're trying to repair your machine and this is what's going on in here uh it's very unhelpful okay motherboard is out there's the bad Shield we'll get rid of that ouch looking at the bottom here sorry about the glare we have some Rust in the corners so this machine obviously has been exposed to a little bit of moisture and then looking at the top cover here all the hinges are there these standoffs are fine this one is actually broken but it probably still works with a long screw and it has snapped off here but I think with a little bit of acetone thing I could probably get that back on all right so one negative about this little oscilloscope here is it is using the composite video input on my retro tank here so I can't easily have both that up and also the 64 because currently I only have one retro tank actually hooked up you know what I have another retro tank my old one and I have a multi HDMI capture card now in this machine so I can plug both in let me get that set up so the oscilloscope is currently being captured through the Retro tank down here which is what you see right now and if I switch this now we're looking at the video output from this Commodore 64 going through my old retro tank so let's turn this thing on uh no signal okay there we go so we have a black screen with the line so that's interesting that that no signal thing popped up I hadn't seen that yet that's uh something on the capture card I guess but yes it's kind of cool I can just switch back and forth between the 64 and the little oscilloscope so let's take a look at some of the signals on this machine so this thing is set up I think I was looking at the two megahertz signal which is actually appropriate let's start with the clock signal I have the probe clipped onto this which is ground on my phone here's the pin out for the processor so the reset line is pin 40. we want to check that right so I'm going to hold that on there and I'm going to power cycle the computer and it should stay low for a second when we turn it on and then go high and it does exactly that so we know reset is working perfectly we're looking at Phi 2 output which should be the one megahertz and that's looking good and then we have pin one which is the one megahertz clock input this is actually what's coming directly from the vic2 the Phi 2 is actually generated by the CPU which is why it looks a little bit different all right so the first pin we're looking at is data line zero let's zoom out a little bit on this so I like how you can zoom in and out very easily without having to like go into a menu or anything to be honest the handtech portable scope I have is harder to use from a UI perspective than this so right now we're looking at I'm turning the machine off and on is just typical activity on the CPU I'm looking for anything that looks stuck like if one of these was just low all the time or high all the time that could be something that's shorting that line high or low now what's interesting about this scope is it seems to have persistence even when I have no persistence set at all if I come on and off the pin you know we can get a glimpse at what actually is going by but it's harder to tell once it's running at full speed like this so I don't I don't totally love that still though things look okay on the data lines nothing looks out of the ordinary I think I'm on the last one there let's take a look at the address line so here we are in address line 14. now you see that like kind of weird slopey thing there again it's I don't know it's a lot kind of hard to tell here what's happening let's adjust the trigger which I'm not exactly sure how to do do I hold this button down pushing up or down moves the entire waveform up or down and left and right moves your view through the 128 kilobit buffer okay take a look at this so there are actual second functions where I guess you hold down a button and push another one so Power Plus up and down actually moves the trigger level oh there we go right cool all right so moving the trigger down helps now we're actually looking at exactly what I wanted to see so that weird like rise there is actually okay that's a pull-up resistor I'm pretty sure and um when the bus floats it slowly pulls it up which is why we're seeing that slope and I think it's on only the high address lines so that was address line 14 and this is address line 15. and this looks a little strange so first off we're only seeing three volts maximum on here but then we're also seeing that two volts in the middle and a pull-up resistor should pull it all the way up to um well five volts or thereabouts so this whole two volt thing is weird I'm going to power cycle the power uh yeah this is very suspect I don't think this is this is right so we take a look at the address lines we're on 13 that looks completely normal 12 11 9 8 7 I think we're on six and it looks a little weird let me go up here certainly is like a lot of undershoot there see how it's dropping way down below interesting I wonder what that's all about I guess it's kind of normal uh I don't know what I think I'm on like five maybe four three oh do you see that how it kind of came into Focus that was because there's a bit of oxidation and I wasn't pushing hard enough that looks good too I think we're on zero or one no that's zero now we're on zero and the next one is VCC so that's just five volts so all of the address lines are looking fine except for 15. that's 14 and there it is 15. all right here's the schematics here so let's take a look so we have address lines here and they're kind of multiplexed up here oh you know what look it only goes up to a13 a15 is not in play on the second page here is a 15. let's take a look at where this goes so it's not there it's not on any of those ICS let's go back to the other page so there it is there's the address lines they come in it doesn't go to the ROMs they are not definitely not on those address lines but if we go back here it also goes up here and look at this there it is on U13 one of these multiplexers so goes into these and then what comes out is the MH lines which are the multiplex address lines that are going to the dram so U13 so right there is u15 now if you've seen videos of mine before often those chips not often but sometimes those chips are Moss replacement parts they're always a 74 LS 257 but the Moss version is notoriously crappy and goes bad and then takes out the whole system or you get garbage on screen stuff like that it's still possible though that this Motorola chip has failed on that address line it's an input into this chip right it should never be actually doing anything to it but maybe there's something failed in that chip and it's holding it there at uh whatever the two volts we were seeing if I turn the computer back on I'm just going to see if it gets extra hot there's another one right down here let's just see if it's warm it's not warm but let's take a look at Pin 11 and there we go we're seeing that weird signal so what I'm going to do I think is clip the leg the pin 11 leg on this mux here and let's take a look on the CPU and see if that cleans up this particular signal but actually before I do that let's just take a look and see where else a15 is used because oh it's also used on the pla of course it would be so the pla could also be bad now it also goes to like the cartridge Port that's what this is down here well nothing is plugged in there so that's clearly not the problem I don't think it's necessarily used anywhere else just quickly taking a look here yeah I really think it's just yeah it's not on the Vic it's the PLA and it's on that particular mux right here so which one is it neither of these are in sockets so it could be either one now what's more likely to fail the pla is is more likely to fail unfortunately so I think I'm gonna cut the leg to the PLA and not to this mux and if nothing changes after cutting the pla lag then I'll reconnect it and then I'll cut the legs of this mux and then we'll see what happens sorry there we are I'm on pin four on the pla right now and I'm going to cut the power on the machine and I'm going to snip snip with these cutters here already I think it's done so let's take a look at this pin on the pla okay it's doing nothing so let's take a look on the underside well would you look at that that signal let's go to the CPU on address line 15. that signal now looks normal so I think that pla has failed now I can use this little tool here and I can try to short the leg and we can see it there we go I've reconnected the pla leg and I've disconnected it that is not normal so I think that pretty much confirms that this pla right here is a goner so time to take that out and it will pop in uh one of the modern Replacements and this should fix the machine maybe or there's another fault I guess we'll find out all right jump cut later the pla is replaced there it is I took it out I actually added a pin back onto there so we can test this in the socket socket is installed and we hadn't yet looked at the back side of the board because of course it had the RF shield on there which I have since removed the back of the board looked good there was quite a bit of flux residue on the hand soldered Parts on here so I actually cleaned that off with a toothbrush while I was cleaning up the work I had done on the sake here now I'm going to say that this board has actually had a little bit of rework done down in this section it was probably done during a QA process after the wave soldering that put most of the parts on this board someone probably just went over this part by hand because it wasn't quite done properly definitely it's not all the pins so I think that these chips down here are likely original notice that the RAM chips don't match but that was pretty typical for Commodore back in the day alright so with the machine on let's look at what is a15 I think that's it right there doesn't seem to be doing anything only Power Cycle it of course with the pla not in there yeah machine's going to do strange things but at least we're seeing a good 5 volts I'm going to say that that address Line is now working fine I mean we kind of validated that was the case by cutting the leg off of this pla all right let's go into here where I have some Replacements we're going to use this one the pla advanced okay there it is and the board nice and easy let's turn this on and I'm going to switch this over to the video input and look at that it freaking works that was it yeah so definitely a bad pla chip and I'm pretty pleased with what we saw with this little oscilloscope there it led us right to the problem well of course it led us to the pla being bad or one of the mux chips but I took a guess that it was the pla cut that leg and then the line returned to normal and then there we go now I have mentioned this before that I feel that these cheap oscilloscopes have a really good purpose and this one being super inexpensive really competes with a logic probe when it comes to diagnosing a system now logic probes have audio cues on them so you can very quickly go down a row of pins and hear if they're low or high or pulsing but the thing is I'm pretty sure logic probe if we had touched that pin that was on this bad pla here it would have just showed pulsing but we needed to actually visually see that the signal wasn't good to know that basically there was a problem with that signal there now of course if you're not familiar with how the Commodore 64 looks you might be tripped up by say that pull up resistor which is that curving Trace we saw the thing is though that one address line did not look like all the others and when you see stuff that's like 2 volts two and a half volts on TTL and it's not going higher than that that's a red flag right there and that's where the oscilloscope comes in really handy to give us an idea that there's actually a problem there before I plug the diagnostic test harness in I want to see what a higher clock signal looks like on this cheap oscilloscope remember how it said it was good for 120 megahertz which I totally don't believe let's go on to the Vic chip on pin 21 and we should be seeing like the output of this Crystal oscillator right here which it actually is counting as 14.3 megahertz why don't we try the auto function on here let's see what this does oh there it is so it's actually showing 14.3 megahertz and the waveform shape which is a square wave going into this it looks okay notice how it always has 14.4 or 14.3 megahertz so there's not enough digits on this particular meter to be able to adjust a crystal oscillator or exact frequency using the variable capacitor that's on the board here but it's definitely working and let's check out pin 22 which is 8.0 or so it should be I think about eight point something megahertz and yeah that signal of course looks good as well since of course it's even lower frequency than the other one I'm honestly a bit shocked that this thing can actually measure frequencies more than a few megahertz okay back to the machine let's do some Diagnostics on this thing let's see what works and what doesn't so easy flash 3 cartridge and we'll run uh some Diagnostics on this thing I have a couple diagnostic images on here we'll just run one of these we'll let it run through and hopefully there's sound let me turn the speakers up oh there won't be any sound because it's not actually connected to the speakers let me just do that while this is testing all right I missed it there it is [Music] all right so the Sid appears to be actually working that's surprising as well all right here we go this is Sven Peterson's new updated test harness is the one the viewer sent in that actually works because my last one was misbehaving all right let's turn this on I'm going to use the joystick and then I'll swap to the last cable here whoa it did not load why that is interesting the easy Flash doesn't work I've never tested this actually easy Flash doesn't appear to work while the harness is connected I am also noticing that my easy flash seems to have a loose part inside I wonder what happened there we'll just grab this so we have dead test and we have the regular diagnostic on this cartridge all right there we go let's turn this on the Elgato capture device there takes a little bit longer to actually start and show video signal than the other one so that's a bit unusual while this runs let's pop the cover off here let's see what's happening inside of this oh it's loose what's loose in here so there it is it appears that an LED came off [Music] uh okay [Music] this machine appears to be fully functional I see it yeah everything passed okay cool um this led doesn't look like it was ever actually soldered in it was just placed into the holes there no it actually was soldered on it just broke off over time okay no problem I can fix that I gotta say I've never opened my easy flash look at the contacts there they are worn wow it's the uh the good quality contacts Eng I think it's called Uh some kind of electroplated gold but that is uh yeah ouch I went ahead and I sold it on a new led the problem is really is that this whole board moves around in the case so if we put it through here like that um basically when every time you insert it it Jiggles around a little bit and the LED which is in that hole there the legs get stressed out so it just it breaks off basically ideally the way this should work is there should be a surface mount LED and then a little plastic light pipe thing that's on top of it that could slide around a little bit to give that give as you put this in and out of the computer next for the contacts what I like to do to clean these is actually a little piece of Magic Eraser and a little bit of deoxite so I'm just going to put some deoxite right here along the top and take my little tiny piece of Magic Eraser I'm just going to wipe it like that look at the filth that just came off let's do the back side same thing just put a strip of it grab the Magic Eraser let's use the other side there look at that Pretty Dirty I know people talk about using an actual pencil eraser but this magic eraser stuff really works well for me and of course everyone knows what time it is we cannot have an actual 64 repair video without it there we go I don't know if you can see that but I put a pink light inside their little pink LED because you know why not Red's kind of boring so pink a little more exciting go down to Adrian's tools and there it is 8-bit dance party plus we'll validate if the Sid sounds good [Music] ah it doesn't sound good okay let me uh connect the audio into the capture device here so you can hear it with a direct capture the 64 is now plugged directly into the HDMI capture device I'm actually back on my other retro tank as well so the video might look a little sharper because on uh the old one I was just using the composite video when I start the 8-Bit dance party just take a listen to the beginning especially it just sounds like some of the notes are actually missing oh [Music] all right well that's kind of interesting actually because while the beginning sounds a little weird the rest of it actually sounds totally fine so the Sid is only marginally not working properly and a lot of people might not even notice that it sounds just ever so slightly off so I'm actually not going to take this out of the board I'm going to say that this is probably good enough to use let me switch over to the Kung Fu flash I have a sid player on there and I just want to listen to a couple other SIDS and I'll try to identify if any of those sound weird as well foreign [Music] foreign [Music] y there we have it that is one repaired Commodore 64 board it just had a bad pla turns out that the Sid if it is slightly not perfect it it sounds pretty much perfect in all the songs I played we have to remember that the Sid chip is actually an analog synthesizer an analog digital synthesizer and there is variance from Chip to chip just because those filters and stuff are analog so it's possible that this one just doesn't work exactly like I expect it to the Sid chip that I'm used to listening to all the time is the one that's in my zip machine which is a 6581 ar4 which is one of the later versions and it just sounds slightly different than these earlier ones but anyhow in the end all that was wrong with this thing was a bad pla which people are going to say not surprised but again the intent with my videos is to show you that you can actually identify that it is a bad pla before you just go removing chips from the board which always brings a slight risk of damage especially if you're not super familiar with how to desolder stuff I took the opportunity on this video while repairing this to test out this little oscilloscope which of course I have on the little finger ring thing here and I gotta say I'm Mighty impressed by this little thing it's not going to be 120 megahertz like it claims I mean I only tested it up to 14 megahertz which is what's available on the 64. but for repairing 8-bit machines this thing really does work well and look let's compare it again to the easy flash cartridge they're basically the same size the oscilloscope is just about twice as thick but look at that it's pretty amazing that something so inexpensive can actually be pretty useful comes with a probe I mean yeah I'm uh I'm Mighty impressed by this so if you are looking for a really inexpensive oscilloscope to help troubleshoot machines like Commodore 64s I gotta say this thing really fits the bill and if like me you have bad eyesight well you can plug this thing into a monitor and then you just get a larger thing roll up a large television set to your bench and this thing will will do that too that's pretty cool so anyhow I think that's going to be it for this video I hope you enjoyed the repair of this Commodore 64 and you saw one of the various failure modes of the pla chip and I hope you enjoyed my little review of this I actually have another as a cheap oscilloscope that I ordered that uh I'll do on the next 64 repair I I think it's kind of fun to repair these with these cheapest Scopes and just to see if this can actually work anyhow I think I've talked long enough about that if you enjoyed this video I would appreciate a thumbs up but if you didn't you know what to do I want to thank my patrons their names are scrolling up the side of the screen they get early access to videos and the higher tiers also get behind the scenes special footage I put videos and pictures and other things up on there about stuff that's going on here in the digital basement so if you're interested to know more about like what I did with my new bench PC up there then it's my higher tier patrons that was able to see the behind the scenes videos me talking about that machine and plus how I edit videos and and other stuff like that so that's going to be that hit subscribe if you haven't already I really appreciate it and comment down below and yeah that's gonna be that stay healthy stay safe I will see you next time bye [Music] we have a little bonus footage at the end here I meant to do this in the video but I didn't so here's the oscilloscope connect it to my 1084 and right now one of the problems is it is not in color and that means that this thing outputs in pal mode now I have the camera set for 150th of a second otherwise we'd be getting a bunch of flicker but my North American monitor here does not have the capability of decoding pal color no matter what the setting is on the back of the monitor it is in monochrome so that is one negative it was capturing perfectly on the Retro tank because it has no trouble decoding pal but it's too bad there's no ntsc setting for this but I guess it kind of makes sense so that means that you have a little bit of a limitation on where you can use this obviously a monochrome monitor like a little uh Apple monitor or something like that would work fine this boxy Phillips brand 1084 has no trouble synchronizing to a 50 hertz signal it just can't decode the color so you're going to get monochrome and you're going to get a little bit of flicker so keep that in mind if you're buying that I'll have to put a little note in the video that it's not ntsc color that it's pal

Channel: Adrian's Digital Basement

Views: 252,542

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Id: Uqrel5fQpK4

Length: 44min 41sec (2681 seconds)

Published: Sat Nov 05 2022