Early 1980s Hitachi VCR Having Video Problems

[Captainclock]

Hello Everyone, about a month and a half ago I had found at a local computer store's freebie pile an early 1980s Hitachi VT-8500A Top-Loader VCR that was in need of a little TLC (it needed a complete set of belts because it wouldn't rewind, fast forward or play) and I just got it in complete running order yesterday afternoon, the only issue is that its not putting out any video when the tape plays just a blank, black screen and that's it, and I'm not sure why its doing that. Its just so frustrating because I'm just so close to getting it running fully and the only thing keeping it from being a fully functioning VCR again is the lack of video playback currently.

Any ideas as to where I should start troubleshooting the no video playback issue?

[Electronic M]

Do you have audio? If you feed it an RF video signal with actual program material will it pass that to the outputs?

I ask because you mentioned in your old thread that you were testing with a flatpannel set and no signal to the VCR tuner....Some flat panels are finicky and won't show a picture unless the signal they get is near perfect.

If audio and video are dead even thru the tuner you will need to get a service manual and a oscilloscope to troubleshoot it....Or get an ESR meter and some new caps and HOPE it is a bad cap and that you manage to find and replace it.

If only the tape video is dead the tape heads are either dirty or bad, or the signal chain has a problem.

[Captainclock]

Originally Posted by Electronic M

Do you have audio? If you feed it an RF video signal with actual program material will it pass that to the outputs?

I ask because you mentioned in your old thread that you were testing with a flatpannel set and no signal to the VCR tuner....Some flat panels are finicky and won't show a picture unless the signal they get is near perfect.

If audio and video are dead even thru the tuner you will need to get a service manual and a oscilloscope to troubleshoot it....Or get an ESR meter and some new caps and HOPE it is a bad cap and that you manage to find and replace it.

If only the tape video is dead the tape heads are either dirty or bad, or the signal chain has a problem.

I double checked it with an older CRT Television and it seems that the Tuner is working fine its just the VCR Part when playing a tape doesn't work right, all I get is a a blank black screen, and no audio either. So I'm not sure what's going on with it, the VCR Doesn't put out any video or audio when playing a tape in either the RF (channel 3 or 4) or the A/V outputs so somethings wonky about the video and audio signal going from the video and audio heads of the VCR to the output signal area.

[Ed in Tx]

Could be some old dried out electrolytic in the E-E V-V switching or muting since it's effecting both audio and video, that's when it switches from tuner source to video tape playback.

[Captainclock]

Originally Posted by Ed in Tx

Could be some old dried out electrolytic in the E-E V-V switching or muting since it's effecting both audio and video, that's when it switches from tuner source to video tape playback.

Where would that circuit be in the VCR? Because I was definitely thinking the same thing but I'm not sure where I would find that circuit in this VCR, that's when a service manual would come in handy...

[Ed in Tx]

You need a service manual to track that down, unless you have a ESR meter and happen find a bad capacitor by checking all on the board.

[Dude111]

I wish you luck buddy!!!

Dont give up whatever ya do!!!! (Try not to)

[Captainclock]

Originally Posted by Dude111

I wish you luck buddy!!!

Dont give up whatever ya do!!!! (Try not to)

I'm trying not to but this VCR is kind of got me stumped at the moment its strange, if it isn't one thing its another thing going wrong with it, first it was the belts and now its video and audio problems... I wish I could locate a service manual for this thing but I have yet to find one for it.

[Captainclock]

OK So a little update on this VCR, I think I found the culprit that's causing the no video and audio issue for the VCR when the play button is pushed, I found a 470 MFD 10 Volt electrolytic capacitor in the bottom circuit board near the back of the circuit board that was bulging like crazy, whereas the rest of the electrolytic capacitors in the unit were just fine, its a Nichicon capacitor and I have a picture of the capacitor below. The only problem was that the circuit its in doesn't seem to be labeled as a mute circuit from what I can see but I'm guessing that's the circuit you were talking about where this capacitor is in.

EDIT: Figured out that the "bulge" on that cap was actually just an epoxy coating of some sort. Took everything apart again that I had unhooked before, and rehooked it up again and now I have video and audio now, but now I have a new problem yet again, it seems that the VCR is playing the tape too fast and I have no idea why it would be doing that. So any assistance with this issue would be helpful. This VCR is 95% running, just that last 5% is what's keeping it from being 100% (which is the issue that I'm having right now of it running too fast.)

[ChrisW6ATV]

As mentioned in the other topic, you probably are not getting the control-head pulses into the rest of the VCR, either from a dirty head or maybe the head or its wiring are bad.

[Captainclock]

Originally Posted by ChrisW6ATV

As mentioned in the other topic, you probably are not getting the control-head pulses into the rest of the VCR, either from a dirty head or maybe the head or its wiring are bad.

Well I've tried to clean the head a couple of times and it seems like its fairly clean (no black residue comes off of it.) And if the tape heads were bad, how hard would it be to get a replacement head for it?

[ChrisW6ATV]

Originally Posted by Captainclock

if the tape heads were bad, how hard would it be to get a replacement head for it?

Before worrying about replacement heads, you should do tests to see if any are even needed. Put an oscilloscope on the output of the control head to see if it is making a signal when a tape is playing. (If you do not have a scope yet, you should get one; many used ones are cheap and not too hard to learn to use.)

Regarding the speed and test-tape issues, the key is to compare using a known-good VCR. For example, if you play a tape recorded on the Hitachi on another machine, does it play properly? (And, switching the speed while a VCR is recording may not even work; you might have to hit Stop first. But, trying each speed available is a good plan.) Make sure your test VCR can play all the speeds of the Hitachi (so, don't use a VBT-200 or VCT-series machine to try to play an "SLP" or "EP" recording).

[Captainclock]

Originally Posted by ChrisW6ATV

Before worrying about replacement heads, you should do tests to see if any are even needed. Put an oscilloscope on the output of the control head to see if it is making a signal when a tape is playing. (If you do not have a scope yet, you should get one; many used ones are cheap and not too hard to learn to use.)

Regarding the speed and test-tape issues, the key is to compare using a known-good VCR. For example, if you play a tape recorded on the Hitachi on another machine, does it play properly? (And, switching the speed while a VCR is recording may not even work; you might have to hit Stop first. But, trying each speed available is a good plan.) Make sure your test VCR can play all the speeds of the Hitachi (so, don't use a VBT-200 or VCT-series machine to try to play an "SLP" or "EP" recording).

No I don't have a 'scope and I have said this several times before on here, I can't afford to get one because all of the 'scopes I've seen for sale on ebay are going for well over $100 and I don't have that kind of money laying around.
As for the test tape I couldn't even make a proper test tape because the tuner on the VCR isn't even working right so I had no way to get a test signal into the VCR for recording test purposes.

[Electronic M]

Originally Posted by Captainclock

No I don't have a 'scope and I have said this several times before on here, I can't afford to get one because all of the 'scopes I've seen for sale on ebay are going for well over $100 and I don't have that kind of money laying around.
As for the test tape I couldn't even make a proper test tape because the tuner on the VCR isn't even working right so I had no way to get a test signal into the VCR for recording test purposes.

About 5 years ago I got my first working scope at a radio swap meet for $50 (and a later got another for cheaper). Look locally. Check craigslist, swap meets/hamfests, and schools and colleges surplus equipment sales, etc....Odds are you can find a decent one cheaper than I did.

[Electronic M]

How is the capstan/pinch roller? If it ain't gripping the tape and controlling it's speed then the take up reel may be what is moving the tape (something that should not be allowed to happen).