Seismic Audio Plate Amp no drive

[tdlunsfo]

Subwoofer section had blown outputs and drivers plus burned traces on the power supply board. I replaced and repaired everything, but subbed mje15032/33's for the driver/predrivers. The signal looks good until a load is hooked up and then it collapses and never attempts to draw any current. I've checked all my emmiter and base resistors, I have no DC offset, the opamp has been replaced, bias transistor replaced. I'm starting to think these mje's are just different enough to keep the amp from working. What am I missing?

With scope attached at the amp output,
No speaker load:

With Speaker load:

[Jon Snell]

Are the current limiters OK?
If they are short ciruit, quite likely from the described carnage, you will have no current to drive the output transistors.

[g1]

MJE15032/33 for 2SA940 and 2SC2073 ? They look close enough to me.
Does the bias adjust pot change the voltage across emitter resistors of output devices?

[tdlunsfo]

Are the current limiters OK?
If they are short ciruit, quite likely from the described carnage, you will have no current to drive the output transistors.

Welp... this was it. Sure enough, they show shorted. I was positive I checked these and at one point I even desoldered the emitters just to rule them out. I removed them from circuit and voila... wattage.

[Jon Snell]

Don't forget to replace them ... or ... didn't they work?
Whoops!
Another not so good design that failed in a spectacular way

Joking asside, pleased to help.

[tdlunsfo]

I replaced them and amp is back together. Sometimes a man just need another set of eyes to get his mind back in line. Much appreciated.