Hello, I have another taramps on my bench. 2 of the traces were burned away I had to repair them, crudely, the 2-10 ohm resistors in the +/- 5 volts circuit, they were reading in the kilo ohms.
I've managed to solder on the IRS 2093 IC, all the relevant voltages are there. VCC 1-2 is 14.2 volts, plus both +/-5 volts and 10.1 volts on the CSD pin.
But with all that the audio sounds distorted so a checked the drive voltages and they're are like 1 volt or .4 volts or even 2 volts.
I've managed to solder on the IRS 2093 IC, all the relevant voltages are there. VCC 1-2 is 14.2 volts, plus both +/-5 volts and 10.1 volts on the CSD pin.
But with all that the audio sounds distorted so a checked the drive voltages and they're are like 1 volt or .4 volts or even 2 volts.
Attachments
10.1 max on the CSD? That's borderline. It need to go to 0.7 of the VAA voltage. How long did you give it to charge?
Long enough, I tested the other voltages prior to its. How do I properly test for CSD voltage? Negative probe to ground?
When you drive a signal into the amp, do you have a rail-rail square wave on the output transistors?
Did you test for drive with the scope across the gate and source terminals of the FETs?
Did you test for drive with the scope across the gate and source terminals of the FETs?
Did the original 2093 cause the 10 ohm resistors to fail?
Is this a new 2093?
What else failed in the amp?
Do you remember what the CSD voltage was in the other amp?
Is this a new 2093?
What else failed in the amp?
Do you remember what the CSD voltage was in the other amp?
The resistors are still good, the 2093 however was burned.
Yes.
R89, R85 and I think R56 and 60.
About the same as the last 2 i repaired.
Yes.
R89, R85 and I think R56 and 60.
About the same as the last 2 i repaired.
I can't remember if I changed them, but they measured okay, also that area looked heat stressed, because the pads for the 2093 that's connected to those were burned away.
Connect a jumper or solder bridge across it.
Measure with a multimeter from gate to source for all of the output FETs. Do any read near 10v DC? Don't let the probes slip.
What's the rail voltage in the amp? Black meter probe on either of the center speaker terminals, red on the center legs of the rectifiers.
Measure with a multimeter from gate to source for all of the output FETs. Do any read near 10v DC? Don't let the probes slip.
What's the rail voltage in the amp? Black meter probe on either of the center speaker terminals, red on the center legs of the rectifiers.