Behringer Euro Live B1800D PRO 18" subwoofer help SMPSU28 and P0981 pcb's

[shepo1]

Hi
I have been looking around and found this fourm.
I have a euro Live 1800D 1400W powered sub.
Unit would turn on but then just Clip light would come on.. then it would cycle.
I could here a pop from the speaker.
Speaker is good.
I pulled the amp.. Found shorted fets and damaged Gater drive IC
Replaced Fets and Gate driver.. still keeps cycling on and off.
Finally destroyed more fets..
I found problem with IC that provides PWM signal to drive IC's..
Fixed that .. now appear to have good signal to Gate Driver IC's
Amp still cycles .. I can see for a brief moment. a Sign Wave at ouput.. but then OC protection cycles again.
Then It blew up again.. I can seem to find out why this keeps try to OC protect.

Does anyone have schematics for this.. This is a class D full bridge config..
PCB types are
SMPSU28 ( POWER SUPPLY)
P0981 ( Power amp and signal pcb.

Thanks for any help..

[Jazz P Bass]

Have a B1800D that went belly up.

I found your post over at DIY Audio.

Behringer 1400W Class D for B1800D Repair help!! - diyAudio

Interesting how the bootstrap capacitor would not let the one side turn on.

And good old Behringer, copying the Ampeg SVT-7, albeit with a higher voltage power rail.
+ & - 75Vdc.

SVT 7_ Main Bd.pdf

Note: if repairing one of these or a similar amp, the Hi Lo driver, IRS20955S IC is no longer available.
It has been replaced by IRS20957S.