JL HD750/1 burned Power supply

[Achim1409]

So, PS is working fine. Removed Audio section, uncluding drive ics. Some fets where short.

Problem still is, that the amp is not switching of. If i remove remote, the amp still producing rail and pulls 0,5Amps... LED is off, when i remove remote..

 

[Perry Babin]

Are you sure that the FETs for the rail supply are still being driven after removing remote?

 

[Achim1409]

Yes, it's regulating all the time.. Amp draws 0.5 to 0.7 all the time. Rail voltage is present, and waveforms at the ps fets.

 

[Achim1409]

Repaired PS completly, changed Audio part irs and mosfets.. I have Amplitude from the IRS to the mosfets... But no Audiosignal to the irs... Also the amp still dont switch off..
The LED is flashing red and green, but still produce rail, and also the audio part ist still working... But no audio

 

[Achim1409]

Found the problem from the remote circuit. R505 had a bad solder joint, so the signal wasn't pulled down anymore.. Now I need to find out, why I don't get audio to the drive ics..

 

[Perry Babin]

Are you getting any pulses to the output driver ICs?

 

[Achim1409]

The pictures shows the pulses at the fets..
At the input of the drive ics, I have also pulses,
But no audio...

 

[Perry Babin]

Do you ever get any modulation of the square wave at the driver ICs if you drive a signal into the amp?

Try all switches and pots in all combinations.

 

[Achim1409]

Now it works some switch for filters are not OK.. I will test the amp later.

Thanks again Perry