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Early 1980s Hitachi VCR Having Video Problems
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? |
#2
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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.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#3
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#4
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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.
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#5
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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...
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Audiokarma |
#6
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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.
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#7
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Well That's going to be kind of tricky because from what some of the people on here were telling me, the service manual for the Hitachi VT-8500A was only available as a seminar handout and I wasn't alive in the early 1980s to be able to of acquired one, and I have no idea if sam's ever covered this VCR or not in their photofacts, and even if they did I can't afford to spend $25 on their website to buy the manual.
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#8
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Don't now about that Hitachi thing we had the VT-8500A manuals I used many times since I was the one there that worked on the things and it was a popular model. There might have been a training manual that was passed out at training seminars. That was pretty common. We were an authorized Hitachi servicer, had a subscription to the printed manuals as long as they were available in printed form.
Anyway you might search ebay and then save the search, set it to email you if one ever shows up. Meanwhile I will look in my old pile of manuals next time I drag all that stuff out to see if that one escaped the dumpster... |
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#10
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I wish you luck buddy!!!
Dont give up whatever ya do!!!! (Try not to) |
Audiokarma |
#11
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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.
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#12
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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.) Last edited by Captainclock; 12-21-2015 at 12:56 PM. |
#13
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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.
__________________
Chris Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did." |
#14
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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?
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#15
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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).
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
Audiokarma |
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