Tweet
I have a Peavey M-3000 that was working and then stopped working and the Clip/Compression light came on and remained on.
I pulled the 87478 chip and did some checking:
I have less than 5mV on the output without speaker load. As the amp is very similar to the 400 B/H board, I checked the voltages listed on the BH400 schematic against the M3000 board
and they they are very close (within 2 tenths of a volt). When I apply guitar input without a speaker load and turn up the volume, the LED meter shows signal at the output.
I also tried another TL074 and the clip light remains on.
I am somewhat stumped as to how to proceed with trouble shooting. The Clip light comes on without signal and very little DC on the outputs.
I'm kind of down to Q1, Q2 and Q4 as the culprits.
Can someone please provide some guidance how to proceed with this problem.
Any ideas and advice is greatly appreciated.
I pulled the 87478 chip and did some checking:
I have less than 5mV on the output without speaker load. As the amp is very similar to the 400 B/H board, I checked the voltages listed on the BH400 schematic against the M3000 board
and they they are very close (within 2 tenths of a volt). When I apply guitar input without a speaker load and turn up the volume, the LED meter shows signal at the output.
I also tried another TL074 and the clip light remains on.
I am somewhat stumped as to how to proceed with trouble shooting. The Clip light comes on without signal and very little DC on the outputs.
I'm kind of down to Q1, Q2 and Q4 as the culprits.
Can someone please provide some guidance how to proceed with this problem.
Any ideas and advice is greatly appreciated.
Comment