A Messed Up Commodore 64 - How I Restore a C64

today I thought I'd do a video and show you how I restore and repair a commodor [Music] 64 so what I'm going to do is I'm going to do a repair on this machine I have right here and you guys are going to love this thing so I went and found the nastiest commodor 64 I could find so this will be fun we'll go through the full process of restoring and repairing this machine so both repairing any faults it has plus also restoring it to the best cosmetic condition I can given it state so without further Ado enjoy this oh how's this look o h this is the nastiest Commodore 64 I have ever seen and if you're wondering about this stuff I'm pretty sure it's mold was nasty this thing is just gross so when I I got the Stone Collection this is one of the machines that was underneath the table in the back corner where the leak was so it was a really really nasty space um it's kind of interesting right here it's got a label on it says screen freezes up occasionally or goes blank then comes on again revb 8 of 91 then under that it says no video and this is a Kennedy K through1 18 School District machine so Kennedy's a middle school here in town uh cm34 5 school district 4J Eugene Oregon how's a Eugene Public Schools property tag 84 0258 and serial number is p0141 19802 and in typical with American machines it's just a label stuck here because they're too big to fit in the spot that was molded for them on the back I've got a bit of copper foil sticking out of the cartridge Port the RF modulator is not too rusty oh things look nasty inside of here though now one thing that this machine didn't come with but is very important to talk about real quick here is power supplies basically it comes to this there are a lot of options for Commodore pit 64 power supplies like all of these so it's very likely that if you've got yourself a comodore 6 4 that you going to repair it probably came with a power supply that looks something like this this is what's commonly known in the commer vernacular as a black brick of death and this one really really really lives up to that name and if I plug this in and check the voltages on here this power supply puts 12 volts out where it's supposed to be five if you plug this into a commodor 64 this is going to kill a lot of chips on your machine so you got to be really careful with these now what I recommend you do if you don't have a good aftermarket Supply and you don't want to spend the money to buy one is go to Ray Carlson site I will link it down below and buy yourself one of these this is Ray Carlson's commodor saver it simply plugs into a power supply and then plugs into the commodor 64 and what this will do is if your power supply is putting out too much voltage this will not let it through now another thing you might get which is really nice is you might get something like this so this is a vintage replacement supply for the Commodore 64 and the nice thing about this one is that it's serviceable it's nice and light it's a switching Supply I can pull this apart replace Parts service it and check it you might also get one of these this is a later Supply they are reputed to be more reliable but still possibly problematic and this came with a 64c so you might see a white one if you got a 64c and this one reads good so one other the thing I should mention is that there are some tools you're going to need and there's a lot of tools that are nice to have but not absolutely necessary first of all to clean these machines it's pretty basic stuff you'll need some r bags you'll need some Q-tips some brushes in this case this is just a detailing brush I use on cases this is an antistatic brush that can be used on boards this is a uh cranial brush and then for cleaning supplies you're just going to need like 99% isopropyl alcohol and some Windex just basic Windex with ammonia works great now other tools that can be nice to have are the dead test and diagn nostic cartridges and these especially the dead test can be really a timesaver and can be had off of eBay really inexpensive in fact what you can do is get yourself a combo instead of two cartridges like I have here they make a combo cartridge with a switch on it you switch it one way you got dead test you switch it the other way you have the diagnostic or diag cartridge to go with a diag you don't need to have a harness but it can be really nice I use this harness which I got from Bill Pelton off of Facebook uh the nice thing about this harness is it doesn't have wires so it's just really easy to use um without the harness you're going to get some tests that come back as failed but if you look at up and know which ones will'll show has failed it at least can give you some information with just the cartridge but a diag is isolator and I believe you can get a cartridge with the uh harness for under $50 another thing that's nice to have is some kind of a flash cartridge I use the easy flash 3 there's a few other options out there it just makes it really easy to load up stuff I have a whole bunch of tools on here diagnostic tools that I can just plug this into the cartridge Port turn it on and go also just a regular cartridge in this case I have Moon Patrol um Zakon is I think the uh standard but I haven't come across that one yet but just a cartridge cuz sometimes a machine will work with a cartridge when it won't work without that just has to do with the way the machine is wired uh finally if you're going to fix these machines you're going to need to have a few Basics so let me move this out of the way so you can go with a soldering station like this if you're going to do a lot of this I recommend it if you only plan to do the one machine just get yourself a basic 15 watt or 20 watt soldering iron so I like this Weller by the way it looks there are a couple other options out there I'll link them in the description below so that's s there finally you will need at a minimum a basic electronic meter this one's a little bit fancier than the one you'll see I started with earlier in this uh Channel's history um the advantage of one like this which is about $150 is that it's a lot faster uh finally your going to need to be able to display your output on a screen and I recommend a Commodore 1702 monitor if you can find one that's working if you got to go with an HDMI monitor which I think is a terrible experience it brings out all the flaws in these old machines some of which I don't consider flaws because they were not visible with a real CRT so you can use something like this this is the cable I made in an earlier video and this this is a retro tank 2x Pro so with a special homemade cable that goes from the Commodore video out to S video a retro tank 2x Pro for I think they're around 150 bucks these days this will connect to the HDMI I can run it straight into my monitor and bada bing bada boom I can see if it's working and this just Powers off a USB this is by no means a comprehensive examination of the tools you need I'll do a video in the future where I kind of go over all the tools I use and the ones I consider absolutely necessary ones that are nice to have and ones that are convenient but you know you can do without now we'll take a look at inside so this is probably a sign of things to come but these screws are all quite Rusty let's see what we will see go you guys get to see it before before I do what do you think am I going to like poop bricks oh I expected worse than that although I do see a lot of grime and rust especially right there all kinds of white crusty buildup on the power it's like a couple of the RAM chips have been replaced in the past the processor the Sid chip and one of the CI are socketed the rest are not and then let's go ahead and get this out of here so I can see what I'm doing now the internal screws are not Rusty although one of them's missing the fact that it said chips on the side kind of makes me a little nervous hopefully that doesn't mean this thing's been scavenged for parts I think maybe that was just its future but it got shoved Down Under that table and hopefully never fulfilled that future and I'm going to show you another machine in a little bit that I worked on that had so many bad chips that it's going to be very difficult if not impossible to repair it for a for a reasonable price W this thing is like glued down in here wow no there's still a screw in it hey idiot one more yeah got something in my mouth gross so this looks like what I was seeing from ants like you may have seen that Amiga 1000 with the ants so this is going straight in the trash all right hey look it's Rusty surprise surprise okay so lots and lots of nasty debris in the bottom of the case you see so this is going straight in the Ultrasonic Cleaner what I do is I take the cover just knock off the very nastiest stuff now there is nothing that says you can't just clean the cover right here in the sink I usually start with Dawn and then after I use the dawn I move on to use uh simple green or just Windex but a tool that's nice to have but far from necessary is ultrasonic cleaner you don't need to have an ultrasonic cleaner but I knew I had a lot of machines like this although this is the worst one I could find and they're gross and on top of that with my business I had a 5gal $1,300 ultrasonic cleaner for for like 25 years and it's just hard to go back once you have that convenience this is an inexpensive about $350 unit I think it holds about two gallons it's just big enough to run a Commodore 64 board or cover in it in two passes so it has to lean out and when we start it it'll run for 6 minutes then I'll flip it around run it for six minutes more and then I'll rinse it off and clean it from [Music] there what a lovely noise also want to get the keyboard off of here and get the top case cleaned basically I want to get both cases cleaned because it's nice and sunny out and while I'm repairing the machine these two case halves can enjoy a nice sunbath while they generally untan now they'll uh get rid of some of the yellowing I'm not going to retrobrite them probably um I generally don't retrobrite things unless they are just beyond saving um in this case I want to keep this machine's history I want to keep it school district affiliation intact so they're just going to get cleaned and then uh Sun brighted now the uh the Kennedy's written in Sharpie and that's unavoidably going to fade a little bit but I want to clean it it's just too gross to leave it that way the label here does have to come off and it's probably going to be like crusted on there permanently looks like it's going to come off okay it's still a little bit tacky it's not totally crusty and dry which is unusual so that needs to come off and that went on after this machine was yellowed or the machine has yellowed regardless of it and then this no video that's going to have to come off as well this is an interesting label so I will save it and maybe we can stick it inside later so just like the bottom half which has already been through the Ultrasonic Cleaner this will now go and get rinsed off and go in the cleaner and I'll do that in a minute in the meantime I want to show you then once the parts are cleaned they're not quite ready for sun brighting we still need to get anything that be it oils or or any other crusty bits that'll block the UV from the Sun that is going to leave some discolored areas or some modeling that is probably unavoidable inting this machine's condition but I want to get as much as I can off so start out with just hit it with Windex and then a magic eraser not too heavily but we'll just kind of get all the crud out of the pores and the Ultrasonic Cleaner does a pretty good job but I don't like running these in the cleaner for too long so these have only been through 6 minutes on each half and of course I'm avoiding that cuz I don't want to remove it these are going out because it's a nice sunny day and they'll spend the rest of today and it's it's about 2:00 and all day tomorrow out in the sun all right so it's time for the first bit of soldering for this project and I just need to take the shield off the board I've got my soldering iron set for 400° C which is 50° hotter than I normally use and I also have a heavier soldering tip on it something like this this is much much heavier than the fine tip I usually use for soldering chips but we've got really really heavy ground plank that these Tabs are soldered too so you just need the thermal Mass to get it loose so these take a fair amount of heat to release and I like to add a little bit of solder to it um when I add this extra solder it really makes it flow better so then first I just see if I can pop these loose with just the screwdriver usually you can and there's really no need I don't think to remove the existing solder and it's coming off really easily but usually that's because it's been removed before finally there is often one right here not always but often that one is actually not attached okay if you can see all the crud that just came out from under here this is a paper insulator that's there to keep the the chips from shorten out on the metal shield and then here's the metal shield it's quite Rusty hopefully I can save it if not I should have a couple kicking around I don't usually return the top Shield to a board unless it's the all metal kind but I usually do put a shield on the bottom just cuz it makes it fit the case better and looking at the bottom I can see lots of signs of this that and other thing oh this is nasty see here how much Grime again on these chips in the center so the next thing I like to do is remove that since we're not going to need it and then remove these covers so just a little leverage off of there see we have a ceramic Vic 2 and then we have RF modulator normally when I'm working on a machine like this I test it first but this one was so nasty so now I'm going to go ahead and test this however my perers here says no no no you need to stop the cameras and give me attention she's hurt her foot she has a sprained or broken toe according to the vet poor Luna or I mean poor Agnes all right so making sure none of these caps are shortened out they all look okay almost always bent down like that so don't sweat it and so next what I'm going to do is I'm going to go ahead and move the Sid chip and the reason is is until I know this board is working happily I only thing I lose by removing the Sid chip is I lose sound and I lose paddles I don't care about either I do care if that Sid's good about frying it other than that we look okay so I'll be back in a second and we'll hook it up and run a test and see what happens okay so now for the Moment of Truth I've got it all hooked up I'm running through the 1702 monitor um when I capture I'll do that later but for the first test I like to just use a real monitor the whole capture thing has issues so I like to no if I'm getting a black screen I'm really getting a black screen so here we go three two one oh that is a screen I have never seen before that is interesting to say the least wow strobing this whole thing is flickering and moving but the whole rolling thing is being caused by the phone not sinking all right so I'm going to try one more thing and that is a dead test cartridge no harness or anything I just want to see if we get anything so dead test plugs in here that does exact same thing so other thing I can do is I can remove this CIA which I think has like pretty much a 0% chance but it's socketed so we'll pull it anyway CA has a bent pin that looks like was not very well in its socket y same thing after a 6-minute trip through the Ultrasonic Cleaner top side of the board looks much better but bottom side still just has this nasty waxy film on it and I'm thinking that is just from moisture so what I'm going to do is I'm going to use an antistatic brush wet in an area with alcohol and just see what happens okay so that cleaned up pretty well I'm uh I'm fairly happy with it there are a few things on it that I don't care for so the socket that somebody put on is a double wipe across these cleaned up pretty good but you can see there's some pretty ugly spots like right there there are some not so great solder joints there so going to clean those up I don't think they need to be replaced find out later but uh just so you know I've already hooked it back up and tested it still doing the exact same thing and that's just a check to make sure I didn't introduce new problems okay so next thing we can do is check some voltages first we'll check the 12 volts and the 5 volts off of the voltage Regulators 11.93 looks great and on the 5 volts we got 5.02 five now those two voltages are coming off of the ac9 volts coming from the power supply they are not the five volts from the power supply and that also tells me that the fuse is good there's no need to check the fuse if the fuse was bad these wouldn't have voltages at all and then the next thing we want to do is we'll check the 5 volts from the power supply that's right here is on the cassette Port 4.29 volts sorry 4.92 fo7 volts and just going to check a few ic's going to need my auxiliary eyeballs for that the ROMs get power there 4.9 volts so those are getting voltage typically this last pin on a lot of stuff is the 5vt supply now I think on this Ram it's not all right so we've got good voltages the next thing I want to check is that we have a good uh clock so go ahead and check the clock that's pin one got a nice clock pin 39 so there's a phase clock and then we have the reset all right so the first thing I want to do is I want to check the CPU and make sure that that's working and I want to test these two RAM chips that have been socketed so somebody's messed with them before and while I'm at it I'll test the Vic chip too so make sure this is off just going to unplug it and we'll remove said chips so starting with the hard to get to Vic pull that out pull out the CPU and the RAM chips okay set that aside and I'm going to start with the RAM chips because hey they're the easiest right and test failed expected a zero got a one this one's test much better oh but it still failed just much later in the test so it appears that both of these RAM chips are defective yay boo all right got the zif 64 hey we got a working Commodore 64 look at that no surprise so first thing I want to try is let's just see if our problem is caused by that Vic chip does not appear to be we got a good looking screen and we got a cursor so good that looks all right the other thing I want to test just real quick is the CPU so okay perfect got a good looking c64 so we've got it looks like a good CPU and a good Vic so in most cases when I'm repairing machines I want to work quickly cuz I got got a lot of machines to repair so these are just quick tests I can do to see if they're bad and move on clearly I have a couple bad RAM chips so the next step is to pull this off and try this other machine again with new Ram maybe that's all we've got wrong which would be sweet so the other thing I'm looking at here that I don't like is that's a single wipe socket these are single wipe sockets and this one one soldered in pretty badly um so it takes a long time to replace them but I may find that's necessary whether I want to or not so and then the two new RAM chips because these chips are new the uh legs are splayed out a little bit so I get one set into their slots and then bend the chip down a little bit Slide the others in and there you go boy that went in way too easy that that is a junk socket and obviously when we're repairing these machines there's plenty and plenty of electrical things to fix but a lot of times the issues are mechanical and by mechanical I mean things like bad connections where you just physically don't have the electrons able to get through exact same thing so even though we've got two new RAM chips no improvement and pressing on this Vic is not doing a thing thing okay well now we got through some of the basic checks so the next thing I want to do is go ahead and check the video signals that is something I haven't had to mess with too much so it should be fascinating to work with so what I'm going to do is I'm going to go to the schematic I'm going to take a look see what I should have on the various outputs of the Vic and the support chips and what's going to the RF modulator um so everything coming into the RF modulator I believe is just coming in on these two headers so I can check those to see what I've got and try to backtrack from there and see where I run into trouble okay so this video is getting really long and I actually have to order a part so I'm going to wrap this up for today here and I will have part two out shortly also I'm going to split the keyboard part off to its whole separate video and I'm going to use that as a a detailed how you restore a keyboard and then refer to that in all future videos or most future videos rather than showing keyboard restoration again and again and again and again and again and again and again 80s reference you name it so as soon as it's ready part two will be right here and the keyboard video will be in the description below and thanks for [Music] coming

Channel: RavenWolf Retro Tech

Views: 2,024

Keywords: commodore 64 repair, commodore 64 repair guide, commodore 64, commodore 64 pla, commodore 64 pla chip replacement, commodore 64 pla replacement, commodore 64 restoration, commodore repair, c64 repair, computer repair, retro computer repair, retro tech repair, C64, c64 restoration, retro computer, retro tech, Vintage computer restoration, commodore 64 black screen, commodore 64 fix, oscilloscope, dead test, retro computing, c64 video

Id: arMLbPhyR3k

Length: 28min 28sec (1708 seconds)

Published: Sat Oct 07 2023