The pair I replaced are visible in the picture in #35. They were damaged. I left the pair on the other side alone because they looked OK.
Is this with the zener out?
Are any RCAs plugged into the RCAs?The resistance primary to secondary is generally 120 ohms.
Are any RCAs plugged into the RCAs?The resistance primary to secondary is generally 120 ohms.
Is this with the zener out?
No. I have it clamped to the sink and everything right now.
Are any RCAs plugged into the RCAs?The resistance primary to secondary is generally 120 ohms.
No signal input, Amp powered up (12V, ground, remote) only. Checked again, getting 1.8 Ohms.
Around 1K hum in both channels, little worse on one side. Otherwise seems perfect.
I guess I can take the zener out now and remeasure, I assume it is safe to do so. Or I can just order replacements and revisit later, it doesn't look too good and was right in the most damaged part of the circuit.
Is the resistance reading across the cracked diode and the corresponding diode on the other bank the same?
Yes. They are equal to their respective gate to source voltages on either side.
What resistor do you have in the location where the 120 ohm, 2%, 2w resistor is in this photo?
I have the same. I read low resistance, nearly short, with it in the amp as is.
I guess somebody's shorting that resistor? The working amp I have is reading 120 over that resistor in the circuit.
That, alone, could be the source of the noise. Could you possibly have a solder bridge somewhere?
With the black probe on the main ground, do you have any DC voltage on the RCA shields?
With the black probe on the main ground, do you have any DC voltage on the RCA shields?
That, alone, could be the source of the noise. Could you possibly have a solder bridge somewhere?
I am usually very good about that. I went over the mosfet soldering carefully. That cap in your picture 1000uF I had to lay on its side, due to broken contact as I received it. Perhaps I should recheck that.
With the black probe on the main ground, do you have any DC voltage on the RCA shields?
No.
With the board out, the resistor reads normally. Set the board in the sink, goes short! I guess I have a high joint somewhere wow thank you.
Are all of the insulators between the transistors and the heatsink in good condition?
It is new tape, this:
McMaster-Carr
Clamp the transistors back down and see if any read shorted from their tabs/center legs to the heatsink.
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