It's not that it can be bypaseed by a trimmer, the trimmer is already there (RV601 on schematic). It's just that as long as the PLL output ON/OFF...
Glad you are making progress ! Hope that it will work without replacing anything. IC602 is not critical as it can be bypassed if not working...
This is clearly realted to your symptom. What intrigued me is the similarity between this servo circuit (using CXA1423N IC) and the DD3 and D6C...
I would check Q607 (motor drive), as the emitter of the transistor is connected directly to the positive rail (as is the servo IC) and a short...
Ok, so let me know if I understood your problem correctly: besides the problem with head engagement and high wow and flutter, there is a problem...
Internally it has two 33ohm resistors connected on the outputs when nothing is plugged in. I would check the jack itself for cold solder joints...
Interesting. I have tried mine with Senheiser CX-300 II, I think about 16 ohm. Also tried with Senheiser HD300, 50ohm. Worked with both. When I...
Are you using a 3-pin or 4-pin jack headphones ? It depends on the impedance of the headphones from what I have investigated in my unit. High...
The wow and flutter and the mechanism struggling to engage the head into position can be realted to the broken center gear, depending on how bad...
Given that blown capacitor, I would suspect that the unit was either powered with reverse polairy or with higher voltage. Given that probability,...
Does the unit work perfectly when you press the stop button ?
The capacitor is across the power supply line, so if it's intermittenly short-circuiting it can cause such problem. Desolder it, clean the board...
Step-by-step tutorial for restoring a SONY WM-D3 Professional walkman Parts you will need: MECHANICAL: new center gear, new capstan ring, new...
Hi stef, Unfortunately, you can't buy that volume pot. It's extremely rare, as most parts for these walkmans are nowadays. I don't know what your...
Thank you, @autoreverser ! Indeed it is highly underrated, I would not have looked for JVC walkmans before having this one. After this, I found...
Today I want to share with you another interesting walkman that I got recently on a local auction site. It is the first JVC walkman in my...
@Alim I personally prefer to lubricate the motor bearing when possible (say when possible because sometimes there is very little clearance between...
What I would suggest regarding the white gear is the following (it's part of Marian Mihok repair guides): take it out (it is pressed on the...
Make sure that the belt routing is correct. I will attach a picture from the service manual with the correct routing. There could be one of 3...
Hello ! I think I know what the problem is with your WM-7. You have probably put a high-impedance load on the heaphone output (I see that there...
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