Klh r7000 no sound

I also have a KLH R-3100 receiver. The panel lights and the tuner seems to be working; the speaker relay seems to close normally, but... no sound comes from any speaker. If "balance" control is turned all the way--either way--the unit shuts itself off. It's probably burned out power transistor(s) plus whatever else they took down with them.



I need a service manual or schematic. Anyone know where I can get one?



I know this unit is probably economically "totalled," but I would like to try to fix it. Please don't just suggest that I add it to my local landfill! I also have a KLH R-3100 receiver. The panel lights and the tuner seems to be working; the speaker relay seems to close normally, but... no sound comes from any speaker. If "balance" control is turned all the way--either way--the unit shuts itself off. It's probably burned out power transistor(s) plus whatever else they took down with them.

I need a service manual or schematic. Anyone know where I can get one?

I know this unit is probably economically "totalled," but I would like to try to fix it. Please don't just suggest that I add it to my local landfill!

I Just fixed this problem:
The Klh R7000 has a single sided circuit board and is 'cost reduced & fragile'

I have an Electronics engineering background; so, I approached the problem different.
I checked the power supplies for the PA and then the power supplies for the 144 pin surface mounted chip. There are 3 and they are on a heat sink. They were fine.

The SMT IC selects the audio source and provides tone balance and volume control.

My power supplies were fine and having fixed similar problems in the past: I recognized the 3 wire serial interface between the socketed microprocessor and the 144 pin SMT IC.

Using a Lamp and shining it thru the boar you can see 3 control lines grouped together.

I carefully removed the micro and cleaned the leads and carefully re-seated it in the socket, then I re-flowed the 3 resistors and jumpers involved in the 3 wire serial interface.

So I would re-flow the regulators on the heat sink too.

But mine works again
But be warned the PCB is 'cost reduced & fragile' I Just fixed this problem: The Klh R7000 has a single sided circuit board and is 'cost reduced & fragile' I have an Electronics engineering background; so, I approached the problem different. I checked the power supplies for the PA and then the power supplies for the 144 pin surface mounted chip. There are 3 and they are on a heat sink. They were fine. The SMT IC selects the audio source and provides tone balance and volume control. My power supplies were fine and having fixed similar problems in the past: I recognized the 3 wire serial interface between the socketed microprocessor and the 144 pin SMT IC. Using a Lamp and shining it thru the boar you can see 3 control lines grouped together. I carefully removed the micro and cleaned the leads and carefully re-seated it in the socket, then I re-flowed the 3 resistors and jumpers involved in the 3 wire serial interface. So I would re-flow the regulators on the heat sink too. But mine works again But be warned the PCB is 'cost reduced & fragile'