picked this amp up cheap from somebody online knowing it didn't work.I don't see any fried components and the fets and output transistors all appear ok.This amp will not turn on at all.this is the first time i've ever tried to troubleshoot an amp with a problem of this nature.I was hoping maybe Perry or someone else could maybe point me in some directions.
quick question for you Perry.This amplifier internally consist of three seperate boards.Theres the main board,the preamp board,and a small board near the fan.Do I need to have the fan board plugged in to get proper measurements from the amp or can I leave it unplugged as it makes it difficult to work on with all three boards plugged together
Doesn't the fan board have the gain controls?
If so, the gain may be very low without it.
If you try it, make sure that you have a relatively small fuse or current limiter in line with the B+ source. Sometimes, when components are removed from a circuit, the circuit becomes unstable and oscillates (which could cause damage to the amp). I don't think it will happen here but you should be careful when you initially power it up.
If so, the gain may be very low without it.
If you try it, make sure that you have a relatively small fuse or current limiter in line with the B+ source. Sometimes, when components are removed from a circuit, the circuit becomes unstable and oscillates (which could cause damage to the amp). I don't think it will happen here but you should be careful when you initially power it up.
Sorry I missed one of the posts. I only read the last one.
The center leg should have ~12v on it but the transistor (Q101) is not being driven on by Q403 (small surface mount transistor near Q101). When properly driven 'on', the voltage on the third leg will be ~0.6v less than the voltage on the first leg and the voltage on the first and second legs will be nearly identical.
The center leg should have ~12v on it but the transistor (Q101) is not being driven on by Q403 (small surface mount transistor near Q101). When properly driven 'on', the voltage on the third leg will be ~0.6v less than the voltage on the first leg and the voltage on the first and second legs will be nearly identical.
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