Hello!
A couple weeks ago, a coworker of mine gave me four turntables that he had lying around after I mentioned I wanted to get into vinyl. They are all in various states of repair. Without getting too ramble-y, I fixed one, but the nicest one he gave me has me vexed. I've asked around at Vinyl Engine, but I think that this would be a better area to pose my question, since this is getting more into the weeds. And I'll be completely honest here, I'm learning everything as I go.
It's a JVC QL-F4. The service manual is too large to attach here, but I don't think it will be necessary. When I plug the turntable in, the platter essentially twitches. It starts to rotate without being prompted to do so, but quickly stops, and won't respond otherwise.
Upon opening it up, I found several electrolytic capacitors that had leaked all over the board. I replaced those today. One diode that was pretty well covered in the black gunk broke as I tried to clean it. I have left it for now. Another appeared to be already broken. The turntable continues to behave the same way.
The diodes are a 1S2743 silicon diode and an RD5-6EC zener diode.
My question is in two parts: What does the actual issue sound symptomatic of? I am aware that with broken diodes, it won't work right, but does a brief, initial power up sound symptomatic of faulty diodes? If not what might it be?
Secondly, how would I go about finding replacements for these diodes? They are both discontinued. I have found several different diodes that claim to be the functional equivalent of these diodes, but the values are different for each one. How will I know that I won't fry my turntable?
Thanks.
A couple weeks ago, a coworker of mine gave me four turntables that he had lying around after I mentioned I wanted to get into vinyl. They are all in various states of repair. Without getting too ramble-y, I fixed one, but the nicest one he gave me has me vexed. I've asked around at Vinyl Engine, but I think that this would be a better area to pose my question, since this is getting more into the weeds. And I'll be completely honest here, I'm learning everything as I go.
It's a JVC QL-F4. The service manual is too large to attach here, but I don't think it will be necessary. When I plug the turntable in, the platter essentially twitches. It starts to rotate without being prompted to do so, but quickly stops, and won't respond otherwise.
Upon opening it up, I found several electrolytic capacitors that had leaked all over the board. I replaced those today. One diode that was pretty well covered in the black gunk broke as I tried to clean it. I have left it for now. Another appeared to be already broken. The turntable continues to behave the same way.
The diodes are a 1S2743 silicon diode and an RD5-6EC zener diode.
My question is in two parts: What does the actual issue sound symptomatic of? I am aware that with broken diodes, it won't work right, but does a brief, initial power up sound symptomatic of faulty diodes? If not what might it be?
Secondly, how would I go about finding replacements for these diodes? They are both discontinued. I have found several different diodes that claim to be the functional equivalent of these diodes, but the values are different for each one. How will I know that I won't fry my turntable?
Thanks.
