You have to drive a signal into the board.
With the connections to only ±5v, ground and signal, all you will be able to check is the signal up to output of the LM211.
With the connections to only ±5v, ground and signal, all you will be able to check is the signal up to output of the LM211.
Yes got square wave after giving signal. But then when I put the board back it is going into protection.
You'll have to wire up the rest of the power supply connections to the drivers to test farther.
Did you replace all of the transistors along the top of the board (Q7, 11, 19, 22)? Those commonly cause problems and should be replaced no matter what's being done to the amp.
Did you replace all of the transistors along the top of the board (Q7, 11, 19, 22)? Those commonly cause problems and should be replaced no matter what's being done to the amp.
All pins?
Disconnect the output drive pins.
Do you get a drive waveform on the output drive pins for both drive circuits?
Disconnect the output drive pins.
Do you get a drive waveform on the output drive pins for both drive circuits?
OK. Now connect the two drive pins for one side? Oscillation?
Connect other side. Oscillation?
You may need to drive a signal into the amp to make it oscillate.
Connect other side. Oscillation?
You may need to drive a signal into the amp to make it oscillate.
Without protect pin connected. One side two drive pins connected and no oscillation as soon relay click amp goes into protection.
Other side also same.
Other side also same.
When the drive pins weren't connected and you drove a signal into the amp, did you see a drive signal on all 4 drive pins?
If you have no drive with a higher input level, connect a 10k resistor between terminals 1 and 2 of the TL072. Does that help?