the measurements are made with the power supply disconnected and Q420 Q423 Q419 Q422
as in the picture
as in the picture
You can't rely on the in-circuit readings except for shorts or near-short leakage.
Check the voltages to confirm that they're present and generally correct.
Check the voltages to confirm that they're present and generally correct.
To check the various supply voltage listed on the diagram, the amp will have to be powered up. You shouldn't need to have the outputs in the circuit but after powering up wihthout them, make sure nothng is overheating.
To check the smaller transistors on the main board, testing them in the circuit is unreliable.
To check the smaller transistors on the main board, testing them in the circuit is unreliable.
yesterday I connected the 13 volt power supply consumption 2A
q15 and q14 lm339 was hot
the voltage was at TP7 TP8 of 38.8 volts
today I take the measurements again
q15 and q14 lm339 was hot
the voltage was at TP7 TP8 of 38.8 volts
today I take the measurements again
I need you to measure and post the DCV that you read on BOTH terminals of each of those two resistors. I need you to post 4 voltages. All DCV.
when I tested the amp in 4 ohm load on the 4 channels the only one that went up to 20A in one second!
is it where there is Q420 and Q423
and there was no vdc voltage on the other 3 channels
is it where there is Q420 and Q423
and there was no vdc voltage on the other 3 channels
three remaining channels? I need to know about all other channels. I need to know if there are problems that could narrow down the possible issues with this channel.
yes it is a 4 channel amp I tested the load on 4 ohms on all the channels and the only one that blew the fuses is Q420 and Q423