Calling all badcappers to help me rescuing and restore this oldie! I have an old mid 70's Pioneer QX-949 quad receiver that I am doing as more of a kind of long term go over everything repair / restore. It is in a decent shape too and even everything still lights up. So I really want to get it back working 100% as it supposed to.
The problem right now is that the receiver amp has absolutely no audio. None on the headphone jack either. I turn the amp on and there is no click from the protection relay. The tuner does work, as the needles do something while turning the dial.
So off I go directly to the output of the PA and check for DC voltages. Didn't have to look very long and found on one PA -39V on one of its output pins (pin 22).
I went and took the two TO3 transistors out and checked them in diode mode. Nothing wrong. Checked the driver and nothing wrong there either. So what am I missing? Why is there -39V when there shouldn't be any?
The problem right now is that the receiver amp has absolutely no audio. None on the headphone jack either. I turn the amp on and there is no click from the protection relay. The tuner does work, as the needles do something while turning the dial.
So off I go directly to the output of the PA and check for DC voltages. Didn't have to look very long and found on one PA -39V on one of its output pins (pin 22).
I went and took the two TO3 transistors out and checked them in diode mode. Nothing wrong. Checked the driver and nothing wrong there either. So what am I missing? Why is there -39V when there shouldn't be any?
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