Perry,
It looks like R255 is bad. Its reading way over 1k. Is this a good replacement?
CRCW08051K00JNEAC Vishay / Dale | Mouser
Also R253 are bad. are these a good replacement?
CRCW080510K0JNEAC Vishay / Dale | Mouser
It's almost impossible for the 10k to be damaged. Is it cracked?
Those look OK.
Lift Q217 and Q218 and check for leakage and open junctions.
Those look OK.
Lift Q217 and Q218 and check for leakage and open junctions.
I lifted Q218 and it was within range. I replaced Q218 and now it is good. I will have to order the replacement for R255. Wen testing Q218 is the leg that is by itself the gate?
Use the link on the following page and send a screen-cap after filling in the form.
Basic Amplifier Repair - Transistor Test Applet Link
Basic Amplifier Repair - Transistor Test Applet Link
Perry,
I replace the last resistor and tested the audio and now it is clear. Should I now set the Bias on both channels?
After you have all of the old heatsink compound removed and the replaced, all of the transistors clamped to the heatsink, yes, set the bias. This is how I set it:
http://www.bcae1.com/temp/ausettingbias.swf
http://www.bcae1.com/temp/ausettingbias.swf
Perry,
I know that you told me before to set them while measuring across the dummy load on the power wire. How much voltage change is ok for each bias? 0.10vdc ?
As long as you see a slight increase, that's likely OK. You just need to get the output transistors to begin to conduct (pass current).