SPL Dynamics EXT 3000D

[shirkonut]

Hey, I recently bought a broken spl dynamics ext 3000d and I´m trying to repair it. Does somebody have the schematics of this amplifier?

[audiofanaticz]

I use to have 2 of them like 15 years ago.
Mine went in to protect every other week it seems the last time I fixed them I basically ended up giving them away because I was done with them, and it seems a lot of others had that issue too.

They are just a basic run of the mill board that a lot of other companies used like the American Bass VFL 200.1, one of the older Hifonics models, and a few others. 

Good luck finding schematics though because I rarely heard of those being available for most amplifiers.

[shirkonut]

Thanks for the quick reply. I have never repaired an amplifier before, so this one will be interesting.

[audiofanaticz]

It's most likely the power supply that is blown on it, mosfets, gate resisters, and driverboard.
The spring clips holding the mosfets to the heatsink are always a blast to put back on so enjoy that!
You're going to need a fairly decent benchtop oscilloscope to test components with and to visually see the wave that the amp  is outputting. Without one you're wasting your time.
Typically I would say experiment with a cheaper amp while learning, but those amps are so old and essentially worthless now days so have at it!

[shirkonut]

Actually the power supply side is fully intact, but the square wave of the power supply does not seem very good to me. I probed the wave on the rectifiers, but on the MOSFETs it is no different only with 9V. The Output side is blown. All the MOSFETs are shorted or literally blown. When I probe the Railvoltage on the Output side, I get a positive Railvoltage of around 75V and a negative of only 65V. What could the issue be?