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  #16  
Old 12-21-2015, 10:19 PM
Captainclock Captainclock is offline
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Quote:
Originally Posted by Electronic M View Post
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).
Well I was watching the the capstan and Pincher roller assembly and even tried to see if I could push my finger up against it to see if I could get it to go up against each other more and it seems its gripping properly, I even tried recording a test tape and it didn't seem to make much of a difference whether or not I had switched the speed switch on the fly while it recorded or not it just recorded and played back at the same speed (which was a really fast speed.) Also it seems that the tuner that's built into the VCR isn't working right as I'm not getting any sort of white noise out of it and I can't get it to tune in my converter box for a signal source, it works by letting the converter box signal pass through to the TV itself but it won't go through the VCR's tuner, all I get is a blank black screen (just like I did with the VCR when I tried playing tapes in it before I got that part fixed.)
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  #17  
Old 12-21-2015, 11:08 PM
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dishdude dishdude is offline
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No audio and video is weird, these machines weren't advanced enough to black out the screen and mute the audio if there was no video signal, so you should at least get audio and a garbled picture.
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  #18  
Old 12-21-2015, 11:29 PM
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No audio and video is weird, these machines weren't advanced enough to black out the screen and mute the audio if there was no video signal, so you should at least get audio and a garbled picture.
Well I finally got the tuner working again but of course there's no audio, just video. And I've done some more checking into the capstan and pincher assembly, and I noticed a "track" worn into the pincher roller and also that the pincher roller was pretty hard so I tried using some rubber renue on it to see if it would help the roller grip better and it definitely softened up the rubber on the roller, but its still playing too fast, no amount of cleaning the heads or anything is fixing it. So I'm guessing that the heads might be bad...

Also when I was taking the tape cover off (the part you insert the tape in) I accidentally dropped a screw down into the VCR and I was trying to get the screw out and in the process screwed up the clock display (I accidentally forgot to unplug the unit when I went to retrieve the screw.) So what would of the screw hit that would of messed up the clock display? Also I think that the same incident that screwed up the clock display may have been what brought the tuner back to life minus the audio portion of it.

Last edited by Captainclock; 12-21-2015 at 11:33 PM.
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  #19  
Old 12-22-2015, 12:44 AM
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You probably shorted something out with that screw.

The speed is regulated by the capstan and a complex electromechanical feedback loop that takes in speed sensor, tape signals (control track, etc.), etc. and adjusts motor speeds etc. accordingly. Several different things could be bad, but it's looking like most remaining possibilities are electronic....Those circuits require quite a bit of VCR specific knowledge and test equipment to properly troubleshoot and adjust...Enough so that it may be better to just find another VCR....
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  #20  
Old 12-22-2015, 01:13 AM
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Quote:
Originally Posted by Electronic M View Post
You probably shorted something out with that screw.

The speed is regulated by the capstan and a complex electromechanical feedback loop that takes in speed sensor, tape signals (control track, etc.), etc. and adjusts motor speeds etc. accordingly. Several different things could be bad, but it's looking like most remaining possibilities are electronic....Those circuits require quite a bit of VCR specific knowledge and test equipment to properly troubleshoot and adjust...Enough so that it may be better to just find another VCR....
I see, well would you be interested in it, and monkeying around with it or know anyone on here that would be interested in it? I would hate to see this thing get recycled, because its a complete unit with its original remote and owners manual and everything.
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  #21  
Old 12-22-2015, 03:37 PM
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Quote:
Originally Posted by Captainclock View Post
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).
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  #22  
Old 12-22-2015, 11:55 PM
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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.
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  #23  
Old 12-23-2015, 01:27 AM
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OK. If the VCR has video/audio input and output jacks, you could try connecting a digital-TV converter box. For oscilloscopes, look for hamfests in your area maybe, when you can afford one.
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  #24  
Old 12-23-2015, 02:49 AM
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Originally Posted by Captainclock View Post
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.
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  #25  
Old 12-23-2015, 02:53 AM
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Originally Posted by Electronic M View Post
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.
The key to getting good tools is to, know what you want, and always be on the lookout for it....Just because it's too expensive one place and time does not mean it wont be cheaper elsewhere later.
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  #26  
Old 12-23-2015, 09:10 AM
Captainclock Captainclock is offline
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The key to getting good tools is to, know what you want, and always be on the lookout for it....Just because it's too expensive one place and time does not mean it wont be cheaper elsewhere later.
I have looked locally and most of the schools got rid of any equipment like that years ago, and I don't have any swapmeets near me that I could go to, I live smack dab in the middle of northern Indiana which has nothing in the way of ham-fests or swapmeets for radios and TVs, and the local flea markets and antique stores have yet to have anything like that for sale in them, the closest I've seen to test equipment like what you are talking about was a signal generator at a local flea market, and it was in my price range but I didn't have the money on me at the time to buy it and when I went back the next time when I did have the money for it, it was already gone. So basically where I live it isn't much of a hotbed for vintage test equipment.
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  #27  
Old 12-23-2015, 09:14 AM
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Originally Posted by ChrisW6ATV View Post
OK. If the VCR has video/audio input and output jacks, you could try connecting a digital-TV converter box. For oscilloscopes, look for hamfests in your area maybe, when you can afford one.
I don't think there are any hamfests or radio swap meets in my area, the closest ones that I know of from reading through people's posts on here in VK is in Chicago or near Detroit and I'm not too thrilled about driving to either location by myself because of traffic and because I'm just not familiar enough with those areas to drive in them on my own.
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  #28  
Old 12-24-2015, 01:36 AM
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Well, there is one in La Porte on February 27th. Maybe you will be lucky if you go there.

http://www.lpcarc.org/

http://www.arrl.org/hamfests/search
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  #29  
Old 12-24-2015, 09:17 AM
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Well, there is one in La Porte on February 27th. Maybe you will be lucky if you go there.

http://www.lpcarc.org/

http://www.arrl.org/hamfests/search
OK. Well that's still about an hour away but I'll see if I can make it over there.
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  #30  
Old 12-28-2015, 12:20 AM
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OK So here's something interesting that this VCR is doing now, I went to plug in the VCR and try it out again just to see what it was doing and sure enough the tape was playing and detecting the proper speed now all of the sudden, but here's the catch its gone back to not putting out any audio or video again, but this time instead of the no audio and video signal issue being just in the VCR part, its also in the tuner part now as well, all I get is a blank black screen, just like before, so here's where the interesting part comes in, it seems that when the VCR is putting out the audio and video signal like its supposed to is when the VCR doesn't play and detect the proper playback speed of the tape, but when the VCR isn't putting out any audio or video signals it detects and plays the tapes at the proper speed...

Any ideas as to what would be causing this rather mind boggling issue?

UPDATE: I just figured out what this VCRs problem is I took the bottom cover off so I could get a look at the bottom circuit board to see if I could find what part was shorted to cause the clock display to malfunction and sure enough I found that C549 had a cold solder joint on the positive lead and a lifted trace and no solder attaching the negative lead to the board, and I did notice that it was a newer capacitor replacement as it doesn't match design wise or brand name wise to the rest of the electrolytic caps on the board. So how would I go about repairing this issue?
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Last edited by Captainclock; 12-28-2015 at 12:55 AM.
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