Panasonic PVS7670 SVHS VCR has a few problems

this time I have a Panasonic super VHS machine double knows it doesn't know much about it thinks it may have a problem but doesn't know so we're gonna check this one out see what's wrong see if we can get this one working let's check out and see what I've got this time I have a PVS 7670 super VHS machine it's taped over the record button so they don't accidentally record I guess on it um I got this one to check over I don't know what's wrong with it it just brought was brought in and said please check over so there might not be anything wrong with this but then there might be so let's just plug it in and uh check it over the picture kind of looks to be fluttering a bit just on the blue screen I wonder how the picture on playback is going to be but that doesn't look very good right there that looks like we may have a power supply problem oh there's also a hyperscan feature yeah it uh the regular version of that doesn't sound good does it so this unit does indeed have a problem that's crack this one open and see what's wrong this was making quite a noise when the Head drum was spinning I think this drum might be shot I mean that sounds like something is rubbing on the the Head drum maybe the embroidery Transformers there's no good here the racket it's making patch the picture's shaking like crazy [Applause] let's just pop the top of the head drum off and take a look underneath here this one here I believe the rotary Transformer is actually part of the upper drum if I'm not mistaken on these ones I don't know if I have the right bit in my screwdriver before I remove this I will Mark which direction is coming off so I know which side it's on so we'll just Mark the the shaft in this little side with a little black mark just so I know which way it goes on when I put it back on here's the rotary Transformer on this one it's making the noise is it the motor it could be the bearing underneath I guess I didn't need to mark it because there's an alignment hole right there it lines up with that one it would have been for the automatic assembly but the the bearing is certainly making noise so I'll have to pull the mechanism apart and just take a look underneath it sounds like something's rubbing like maybe something has gotten in between the the rotor and the uh the stator the motor the coil the stator assembly because it just feels like it's dragging like it doesn't spin like it should like that should spin a lot more free than it does so we'll pull the mechanism I want to take a look at the uh the bottom of the drum and just just see if there's something in there that's it's gumming it up so I gotta pull the face off the unit to get into it we'll pull the back of this remote now this machine it would have a lot of hours on it this is used by a company that archives tapes that I do some work for so this is not a low hours machine this is probably a very high hours machine I'm guessing but I know that my archiving machines that I use have got like literally thousands upon thousands of hours just because they're they're in constant use for SNAP forward so I can get to the screws down here and a couple more at the back here I'm going to pull this board out and get that bracket out of the way foreign board take that board out I can remove this bracket so I can pull the chassis just so that I can inspect it all that work just to pull out the chassis it should lift right so it should lift out just like that you want to inspect this motor well I don't have a an allen key that's small enough to fit this it's like to be a one millimeter but I've just been doing some careful lifting up around the edges here prying it down just a bit like this and now see if we can get the the noise to stop does it looks to be out of balance a bit should be a little bit of a low spot right there foreign I think it might have been just rubbing against the quail maybe a bit of a debris or something got on the magnet that's quiet it's not making the sound anymore that is no noise excellent we'll just put the ground the electrode back on again and pop this thing back in and see what it does see that it's nice and quiet and how the pitcher is because you saw how it was shaking before mode switch on this probably wouldn't hurt to be cleaned I can certainly do that while I've got the mechanism out I'll mark it where it stopped because this is where the mechanism currently is as long as I don't move the mechanism at all as long as I don't move the cam gear the modes which will stay there we'll pop it apart and clean it up it doesn't like to be too bad actually but we'll clean it anyway give it a shot of neutral and clean it up foreign just to leave behind as a residue because it does have a lubricant in it and put our switch back to where I left it and put the mechanism back in put the red screws back in the back foreign Supply too we don't know about that yet but those are from 1997 25 years old machine I'm gonna plug it in again see how it sounds this time it's already sounding quieter looks to be playing just fine on the CRT that's why I keep that little CRT here my little Sony this is a super VHS tape I'm playing my little Sony eight inch Trinitron that I got for free about 30 years ago because and the story on that I think I've mentioned this one before anyway that's a super VHS tape playing you saw how shaky it was before and you can hear the drum rattling away now the drum's nice and quiet so this one's fixed anyway this TV so how I got this TV circuit board's got a major break in it it's actually almost broken in two but uh I got it when it was pretty much new customer comes into the TV shop I worked at and they bought this for their that goes for their camper either their camper their motorhome anyway the knuckleheads didn't have the thing tied down when they drove away and they went around the corner and the TV flew off whatever it was sitting on and ended up on the floor and the cabinet's all broken I think that's just a glitch in the tape the cabinet won't stay on the cabinets held together with uh it's got electrical tape and and packing tape on it hold the cabinet together because all this all the screws were shattered all the screw mounts were shattered circuit board had a great big break in it so fortunately it was one that was not that difficult to repair so I repaired the circuit board I killed some lights in there the TV will actually look a little better because it's pretty bright it's pretty bright here in the shop so if I kill some of these studio lights it will actually look a whole lot better than it does with all the lights on anyway um picks it all up fixed the board up told the customer okay the circuit board's broken picture tube's fine everything's looking good but I had to repair the board prepared it with epoxy put jumper wires over the sections that were damaged and we told them okay it's fixed but I can't guarantee I can't put a warranty on the repair because the set was dropped so the board's got a break in it therefore I can't warranty it it could last you 10 years it could last you 30 years it could last you a week I can't guarantee the work because the board's been damaged and they said keep it so Norway the boss would have just sold this to someone right but because um the cabinet was all kind of cracked and stuff he he looked at the cost of replacing the cabinet and uh just said you know what you can take it you can have it of course I didn't get paid for the repair because they didn't they didn't go through with the repair but I got a little little eight inch AC DC TV which I really like and I've been using it here for years and years and years and it's got a great picture and the tracking might be off slightly because I don't have the remote to do the tracking adjustments on this I think you need the remote for this to do it I'm pretty sure you can't do it from the buttons or is that oh maybe these ones will do it yeah that does it there we go there it is you use the uh I guess it's the channel up and down buttons on the front uh yeah the channel up and down buttons on the front these ones these operate tracking when you're in playback this one's nice and quiet now I think I'll clean the heads on it before sending it out grab something to clean the heads with yeah yeah they were dirty and we'll also do the same for the other heads in the lower drum give it one more test anything I put the scope on it and take a look at the RF waveforms looking not too bad so playback might be fine but I just noticed that this machine will not rewind or fast forward if I push rewind it just kind of moves a bit and then stops so we have other problems with this mechanical problems like the uh to pull the mechanism again and check out the clutch huh just when I thought everything was good it fooled me it's not I do believe we have a slipping don't and that's why it's not going to fast forward and rewind this belt is is shot see I can stop it from turning without any effort whatsoever so let's just change it with the belt on this thing see if I can find a better belt for it all right I thought it fitted it with a new belt and this one here is much stronger than the other one it doesn't slip in fact this one here has got so much torque that if I stop the Reel from turning you can actually see the belt it's got a good grip so try that belt and see what happens turn the mechanism back by hand to unload everything so it still doesn't go into rewind or fast forward for that matter when it goes into search it doesn't really even search either it just kind of goes there for a few seconds and then stops but the mechanism never attempts to advance into full fast forward or full rewind I have to think maybe it has something to do with either a power supply issue which is always a possibility could be bad caps on the power supply or it could also be one of these sensors here isn't being read take up for supply sensor now if it was if it was a pickup side you would stop on play so it could be the supply side sensor is not being read correctly or connection problem on it because it has to detect what speed the tape reels are turning before it will go into fast forward or rewind so we're going to check that out and see whether there's any obvious connection issues I'll go over the sensors here just to reheat them and I'm going to check a couple caps in that power supply foreign of course these are wonderful these sets they use these wonderful composite ICS and we all know how wonderful these things are anytime I see these type of circuits I get nervous because you see these little black marks here these are all resistors that are painted onto the board but this isn't what makes these so bad what makes these so bad is what's on the back side you got it our favorites surface mounted electric caps which you know are gonna leak and they're really difficult to try to replace on this because this is not a conventional circuit board this is a piece of ceramic so to try to replace them on here what happens as soon as you start to heat it up the foil the trace is on here which are basically just stuck down right they're not they're not etched like a conventional board and it'll just peel right off so yeah they're always lots of fun to deal with them as a really like a bad design but that was that was Panasonic parade that's why I don't like Panasonic VCRs of this era maybe another little purchase on Marketplace today I don't want to show it to you guys or not nothing real big deal but I picked myself up a little photo uh capture devices they call it a scanner but it's not really a scanner it's more just a camera that's that's in a box basically and it's focused on a 35 millimeter film frame like a slide or a negative and you put them into a into a a holder and it lets you just capture them and I'll be trying that out and see how that looks so I used to have a proper scanner years ago at HP which did a phenomenal job of scanning it was slow it was really slow like it took about a minute and a half to Sky in one slide but it was it was incredibly high quality but unfortunately I can't use it anymore because the drivers aren't available for anything other than I think Windows 98 was the the last drivers I had maybe windows I don't think they made drivers for XP for them 98 95 or 98 it was it was old I was checking some of these caps here see how how they look 0.1.1 some of these caps could be uh like this one here that's kind of gray in color I don't kind of trust these ones when I see them looking like this so we'll just uh we'll measure some of these and see how they look 4.2 oh you can't see my meter but that one that was looking a little high 4.2 ohms so I think I'm going to change out a couple of these caps just to see if that will correct some of the issues that missing's got this one's changing color so I I when I see a cap that's changing color in a power supply I always say question it so let's just pop this one out this is on the primary side so this one here would actually affect the oscillator and could affect voltage okay let's pop this one out and just take a look it's a 4.7 at 200 volts it might be okay because it's relatively low as far as the value goes 4.7 at 200 volts looks like anything under 5 ohms is probably okay but let's just check it and see what it's at so it's at 3.3 it's probably okay because it is a high voltage rated cap and I don't have I don't have one anyway it's 105 degree it's gray in color but I don't think it's discoloring unless it was blue at one time but this may be their the actual color on it but being a 4.7 at 200 volts it's it's within spec so we'll leave that one alone I do want to check some of these other ones over here though I got to pull them out though because uh some of them are in parallel with each other so the thing with this unit is it's playing fine it's just it won't go into full fast forward or rewind and I if I run the mechanism by hand if I turn the loading motor by hand mechanically it goes into the modes so the unit itself is not like the microcontroller is not telling it to go into fast forward rewind it it does the it does the run up like it would checking the reels that real speed to determine where the tape position is and then it just seems to stop at that point and it doesn't go it actually stops I've unsoldered one bead of the caps in the secondary just so I can check them out and see what they look like isolated that works fine it looks okay 0.1 0.1 .1 these all look okay all right there's a couple of caps here that are starting to go a little bit High these two this one here is measuring up at 4.2 ohms it's a 10 at uh let's say 50 volts 10 and 50 so 10 at 50. would be you somewhere between 3.2 and 2.4 and it's a little bit higher so that one's gone up a little bit and the other one here this one here is a 47 it's at 1.6 47 at 50. 47 at 50 should be like you know like 0.68 between 0.68 and 0.56 according to the charts are those two might be starting to up a bit maybe I'll change those two out just see what happens whether it makes any Improvement at all to the operation I don't think it's going to change anything but we'll change them just for the heck of it because we're already in here I got a couple of newer ones that measure really low on the ESR meter so pop these two in however on the ESR meter you wonder compared to the ones that came out so here is the 10 so the 10 microfarad is measuring it at 0.2 and the other 10 that came out of here was what was it at 4.7 or something 5.0 and the 47 that came out was measuring at 1.8 and this one here that's going in is uh 0.2 so as you can see they are considerably in better shape than what came out so we'll try these and see whether that makes any difference too the way this thing behaves all right it's back together enough that I can test it I don't need to put everything in place like that's play I'm going to fast forward foreign this other tape and see what it does play rewind but go to rewind or it's going to stop again you see still doesn't go to rewind and it just does that rewind it just reverses slowly and it shuts down the power goes off that noise that it's making that sounds like the Capstone motor actually that grinding noise sounds like the Capstone motor bearing is a dry this one was sent in to be checked over so I gotta contact the guy that owns it and see whether he wants to continue down that road because as I say this is a bearing is sounding pretty pretty loose that might be part of his problem there's a Capstone motor itself as I said this unit's had a lot of hours on it listen to this if I spin it you think that might be one of the reasons it's not going to rewind a fast forward it's just it's too much it's detecting drag on the motor very likely that's what's happening so I think I'm just going to leave it as it is it plays it doesn't fast forward or rewind um but as you can hear from the noise that this thing's making this machine is just about completely worn out it's owned by a guy that does um he does uh archiving so this machine would have had thousands upon thousands of hours on it it wasn't actually a machine he brought me to repair he just wrote on it test so we've seen what's wrong with this one I mean the drum motor was making a racket before it got that quietened down but that Capstone motor is the bearing itself is shot on that it just makes all kinds of noise when it tries to run at higher speed when the pinch roller is not engaged on it basically and burying itself is chattering the belt was also slipping I threw a new belt in and it changed a couple caps in the power supply that they weren't shot but a little bit off spec oh well um nothing really else I can do on this thing it would need a new Capstone motor and it just wouldn't be worth replacing it because of the age of the unit this is super VHS machine but again these things are relatively inexpensive to replace them and I'm not talking about eBay pricing because eBay pricing is not real pricing eBay pricing is just idiot pricing in other words if you're you're an idiot if you pay that kind of money because these machines do go for a dime a dozen I've picked up three super VHS machines in the last year twenty five dollars for two of them and 15 for the Third so and they were working well two of them two of them were working one with the slvr five I had to put a plastic Gear in um and I had a couple of other slvr fives given to me over the last few years one I kept and rebuilt one I sold so these are not worth a lot of money these machines so I'm going to close this one off and leave it at that it's at least it's playing the tape and that part's working but there's a good chance he's just gonna toss this one out anyway because it's not reliable you can't if you can't rewind the tape what good is it right so anyway throw it together and uh we done with this one

Channel: 12voltvids

Views: 6,924

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Id: YYkEUOdesuQ

Length: 31min 45sec (1905 seconds)

Published: Fri Feb 10 2023