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1970s? Hitachi VT-8500A VCR found today
Hello everyone, today I dropped by my favorite computer store and I went through their freebie pile and sure enough I located a 1970s vintage Hitachi VT-8500A Top-Loader VCR which had a note in it saying "No Power: won't rewind or fast-forward" so I took it home and I figured that it might of just been a bad belt (because I know that these early VCRs had to have a belt for the counter which if the belt broke or was dry-rotted or turned to tar it would make it so that the VCR wouldn't do anything anymore because they usually had a sensor tied to the counter drive wheel that would keep the VCR going and if the counter drive wheel wan't working then the VCR wouldn't play anymore, it was much the same way as your audio cassette tape players were designed to work early on).
Anyways I took the unit apart and sure enough the counter drive belt was bad (it turned to goo) so I replaced it with a rubber band that was similarly sized as the original belt and put it back together and plugged it in and sure enough there was not juice getting to the unit (it wasn't powering on just like the note said) so I checked the fuse which was soldered in place with my multimeter's continuity check and it checked out normal. So my question is, has anyone on here worked on one of these VCRs before and if so was there some sort of common part that failed in these old Hitachi VCRs that would cause this "no power" symptom that could be easily fixed or should I just take it to the electronics recycling center? It would be kind of cool to get this going for watching old movies on or even to use with video games (as it has front and rear AV jacks on it which is unusual for this vintage of a machine). Again any help would be appreciated. |
#2
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Had the same exact unit growing up but it was a GE model 1VCR1012W. It's a 1981 model. iirc, the power supply and huge transformer were a completely separate assembly in the back corner of the unit.
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#3
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Quote:
I would love to get this going to play some of my older VHS videos on. |
#4
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Look for bad lytics. I've had to use an ESR meter to ferret out bad caps get early 2000's VCRs going.
__________________
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 |
#5
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Definitely gotta be bad caps in the ps section. Dealing with that now on a 1986 Magnavox now. That looks more like an 80's unit. I have a 78 rca and its bulkier. Usually 70's models had the rotary knobs and simulated wood grain.
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Audiokarma |
#6
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Anyways the power supply in this unit consists of a giant power transformer (cold chassis not hot surprisingly enough) and a small circuit board with a large 1/4" fuse soldered to it and some capacitors and resistors, and that's it. Not sure how I would go about servicing the power supply in this unit because the power supply board does come out but you have to remove the top and bottom panels and then remove the cover from the back that covers the power supply input (the place where the power plug goes into the cabinet), and then removing two screws from the power supply board and then lifting the power supply board out of the cabinet. Anyways which electrolytic capacitors are going to be the ones that will be bad? Any specific values to look out for that will be bad? EDIT: I found the rest of the power supply circuit, the part of the power supply circuit I was seeing was only part of it, anyways there was a removeable 3A fuse in the other part of the power supply and it was blown so I replaced it with a 4A fuse and its working fine now. So yeah it seems that maybe a power surge must of taken out the fuse because there's no signs of any burn marks anywhere on the VCR. OK so I got the "No Power" issue figured out, now I need to figure out the "no rewind or fast forward" issue, also it seems that when you hit play it acts like its trying to load the tape into the mechanism but the take-up and supply reels don't move thus not loading the tape into the mechanism for it to play, when I hit the Rew. and FF. buttons all I hear is a solenoid click and that's it, its for some reason its not activating the motor that drives the supply and take-up reels, it's almost as if the motor for the supply and take-up reels is seized up or dead... which I hope isn't the case because then that means this VCR is beyond repair because I'm guessing that the motor is NLA. Last edited by Captainclock; 10-01-2015 at 10:45 PM. |
#7
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Good to hear! Another unit saved.
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#8
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Yeah, I just made a couple of corrections since you posted, its powering on fine, but the rewind and Fast-Forward functions are non-functioning, and the play function is also malfunctioning, and I'm not sure why. Its almost as if the motors are seized up or dead.
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#9
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Is the bulb in the transport mechanism lighting up?
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#10
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Yes the bulb in the transport mechanism is lighting up. I have noticed though that its missing a couple of belts at least if not more, the rubber band that I had put onto the counter drive wheels somehow came up missing out of the blue, and then there was a belt that was attached to a drive wheel and the take-up wheel that has pretty much disintigrated, which I don't know if those two belts being gone have anything to do with its current inoperablility issue but I'm guessing that's part of it anyways. I used to have some belts that were the size I needed for those two drive mechanisms but I seemed to of misplaced them, any idea where I might find some extra belts for this thing? I believe they're of the square variety (not flat belts), and they need to be at least 2" in diameter I think. I would think that a standard walkman drive belt would be sufficient enough.
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Audiokarma |
#11
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I'd swap that fuse for a correct 3A version soon. If you replace with higher current fuses there is more probability of one failure taking out more than it should....Not to mention fire....
__________________
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 |
#12
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Anyways I still need to figure out why the unit isn't activating the rewind and fast-forward functions and why the play function isn't activating properly, and I'm not sure where to check first (normally a mode-switch would be responsible for that but this unit doesn't seem to have a mode-switch in it, at least not one like your later VCRs had in them, it seems to have several solenoids to activate the functions with rather than a mode-switch and the solenoids aren't bad because they are activating its just that the mechanism isn't responding in kind to the solenoid's signals. |
#13
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PRB / russell industries is the company making belts - get the belt cross reference to find what belts you need. 4.1MB PDF download....
__________________
Brian USN RET (Avionics / Cal) CET- Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit! |
#14
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Where can a guy get a decent copy of the service manual for this VCR without having to pay for it? I would like to try and locate the service manual for this VCR so I can find the exact size of the belts I need for this thing because that website you told me about that had the belts there only shows sizes of the belts it doesn't go by make and model of the VCR. Last edited by Captainclock; 10-02-2015 at 11:43 AM. |
#15
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Wow .Thats a classic.easy to work on.Big fat power transformer and maybe separate pc boards for each function like the classic Panasonic's have..
WARNING .Wear your steel toe work boots when moving this or any VCR from that era.Your toes would appreciate it. |
Audiokarma |
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