Not a techie, but I love restore threads.
Just fine tuning the volt drop for that 12V regulator, to take a bit of pressure off the pass transistor I should think.Also, what is with the 2W(?) resistors tacked in parallel to the two 390Ω(5W) resistors for R605 & R606?
I have already told you that you have the later revised F2980, are you reading our posts at all?It doesn't look like this receiver has even been touched. I'm assuming these were small changes made spur of the moment at the factory. I'm just going to keep it like it is. Good to know I have a later revised board.
I have not experienced any issues with the traces pulling up at all. I have replaced about 10 components so far.
Turn it on, let it idle for 5-10 mins, set the Bias, then leave it, do not adjust it any further.She's alive! Safely operate, and FM stereo lights up now. All 4 speaker outputs have sound. Quartz lock does not. Does the center dot have to do with it lighting up?
So I checked the bias and after 2 min and it hit 3.3mV. Then at the 10 min mark it tops out at 6.5mv. The service manual says run the unit more than 3 min then adjust them. How much time should I let it run from dead cold, to adjusting them? Granted I have not changed out the trimmers yet, but I will soon. She looks rough, but I will get her in great shape! I have a lot more caps and transistors to do. Then it looks like i'll be working on the F-3000...
I also noticed when testing it out today that when FM mute is ON there is no sound at all through the dial. When Fm mute is off, its working correctly sound and fuzz.
Around the Multiplex chip is a few Tantalum caps, I have found these to play havoc with the muting and cause distortion as well, they are hiding on the tuner board hidden by the F3000 board. It may or may not be the problem.I also noticed when testing it out today that when FM mute is ON there is no sound at all through the dial. When Fm mute is off, its working correctly sound and fuzz.