I am working on repairing my uncles R965 Sherwood receiver which let out the smoke on the front left amp board rail after he spilled a small amount of coffee on it. The resistors on the front left track burned up along with 2 capacitors and a Ceramic Dual Emitter Resistor and all the transistors blew out as well. I ordered replacement parts for everything and tested and it produced very bad audio but it was working. Wanting to check if my replacement parts were bad I used the original transistors from another rail as they are all the same across the amp board. I left all the replaced resistors and the 1 electrolytic cap as the replacements but swapped a orange cap from the other rail. This made a huge improvement on the audio but at higher volume it still produces static/distortion. Im looking for help at what to look into next as i have tested all the resistors ohm values and they are all very close to the other rails. I will include the schematic and the pictures of the board/transistor heatsink array. The main problem I need to fix is the bad audio. I still will need to source replacements for the rail I borrowed from.

List of parts replaced
2SC2922 - Turned out to be a fake clone. Need to source a good one
2SA1216 - Turned out to be a fake clone. Need to source a good one
C3423x2
A1360x2
A1859A
C4883A
Resistors Various Ohms
Dual Emitter Resistor
2 Caps 1 Electrolytic 1 Polypropylene

 

From the diagram , can you measure the voltages around the transistors Q211 to Q216 and compare them to the working channel when you have it assembled.

I would remove any debris from the pcb first and give it a good cleaning with isopropanol.

 

Forgive me as this is a learning experience for me. Is it best to check base emitter collector legs or just checking voltage going into any places around the board making sure they match? I am assembling the amp board and mounting it back to the heatsink and i will post back with readings.

 

Power rail B+ and B- is stable 54.5 Volts DC. I will check the transitors on the outside now. How do you check voltages on the inside transistors? there is no way to safely probe them while live? @Dodgydave

 

Could only check the bottom transistors safely. All the transistors on the bottom row match up to the values of the other tracks.
While i was checking the B+ and B- On the plug itself. I accidently crossed the B+ and B-. It let out a very loud pop and arc but after checking it again it is still reading 54.9V DC stable.
Edit: I just realized am i supposed to be checking while the unit is on or off. I think you meant to test with unit on standby right or on?

 

Standby
B -3.3V DC
Q211 0 0 0
Q212 0 -3.3V DC 0
Q213 0 0 0
Q214 -3.3V DC 0 - 3.3V DC
Q215 0 0 0
Q216 0 -3.2V DC 0
Matches up with all the other tracks

 

Measure the voltages switched on and label the voltage like " Q123 b, c, e
so we know what is what.