It actually has 9540’s on the opposite, it actually only had one bad irf542 and one bad 9540, I installed a irf540 and 9540 just to see it would power and it did.
Hey Perry this amp came back and now it has rail voltage on the speaker output of one channel. Where can I find the drive signal on this amp. I have tested almost every component on the board for that channel and only found 2 resistors of of tolerance and replaced them.
That helps a lot. Is there a way on this amp to check for the drive signal at outputs? I honestly think a piece of solder or a open trace is my culprit.
For some class AB amps, you can see a signal at the gates/bases if you drive a really strong signal into the amp.
If you touch a load across the channel, does the amp try to draw excessive current of does it simply drain off the voltage?
If you touch a load across the channel, does the amp try to draw excessive current of does it simply drain off the voltage?
If I put a 2ohm load across speaker terminal it will draw excessive current, I have powersupply limited to 5amps
Are you sure that you don't have any shorted or leaking transistors? Compare the readings on ohms to the corresponding transistors in the other channels.
Did you try reducing the bias setting?
If not those, which ones are they in the diagram?
Side note, I have the home/commercial 120v version of this amp on the bench right now.
If not those, which ones are they in the diagram?
Side note, I have the home/commercial 120v version of this amp on the bench right now.
Actually it is the one you marked with a red arrow. Bias has no effect on it. There is literally little to no voltage now on the irf9540’s and full rail voltage on the irf542’s not full rail becuase I have it throttle to 2amps
If you bridge the bias transistor collector to emitter with a jumper wire, does the current draw drop?
Good to check the numerous diodes.
Other components might have been damaged from the fly back voltages of the original fault.
DC offset would be assumed possible more failed mosfets.
Or if the frontend components failed. Since you found a bad transistor in the frontend.
Could be out of spec resistors or other bad transistors.
The bad transistor went bad or got too hot for a reason.
Even likely was taken out from fly back voltages as mentioned.
Might be helpful to show what transistor was replaced
and show/ post in the schematic
If typical current sources, if not functioning right there would be DC offset.
Not having full rail but partial rail, as a guess sounds like one or so bad outputs.
Other components might have been damaged from the fly back voltages of the original fault.
DC offset would be assumed possible more failed mosfets.
Or if the frontend components failed. Since you found a bad transistor in the frontend.
Could be out of spec resistors or other bad transistors.
The bad transistor went bad or got too hot for a reason.
Even likely was taken out from fly back voltages as mentioned.
Might be helpful to show what transistor was replaced
and show/ post in the schematic
If typical current sources, if not functioning right there would be DC offset.
Not having full rail but partial rail, as a guess sounds like one or so bad outputs.