Problem with Crate apm-75 monitor

[maxx007]

Hi, this is a great forum for diy er's, could someone help me with my crate monitor I use it with my vdrum set. IT started making a loud buzzing-popping noise as soon as I powered it up so I removed the amp from the housing and disconnected the speakers from the board. I checked the boards for any burnt spots or overheating all looks great. I powered up the amp and checked for DC volts across the speaker leads there was none. But know it won't power up at all. could my power supply have died? I have some skills in Electronics but this is beyond me.

thanks.

[soundguruman]

Basically, crate amps fail quite often. They are not intended for professional use. You can either put money into repairing something that will fail again, or buy a professional monitor.
I would not invest ten cents into repairing a crate product.

[Jazz P Bass]

A common failure on these is the TDA 2050 output IC.
If you can access the ic, with the unit OFF, check continuity from pin 3 to pin 4 & pin 5 to pin 4.
Pin 3 is the -Vdc voltage rail.
Pin 5 is the +Vdc railPin 4 is the output to speaker pin.
If a low ohm reading is read on any off the tests, the IC is shorted.
Install a new one.

[soundguruman]

And a nitrogen cooling system.