Yamaha A-1 Repair and restore: beyond Deoxit

so the amp is off and it measures 68.2 ohm
the other one measures 68.9 ohm
:(
 
FR101 looks burned as you can see in the picture but measures 68.2 ohm
 
yes but im back to no knowing what to do. for a secomd there ithought i'd by a 40 cents resistor replace it and life will make sense again :(
 
the side that is across that heatsink looks brown ... looks burned when i saw i thought that it is the culprit. so the question remains, who done it?
 
Remove the two right channel output transistors. Make a note of which one goes where.

Just unscrew the transistors and remove them from there sockets.Try not to damage the mica insulators.
 
Remove the two right channel output transistors. Make a note of which one goes where.

Just unscrew the transistors and remove them from there sockets.Try not to damage the mica insulators.
It is time to make some voltage checks on various components. Without the outputs in circuit.
 
It is time to make some voltage checks on various components. Without the outputs in circuit.
before i do that let me tell you something. i apologize if this will throw you off or just plain annoy you because it probably is due to my amateurishness but i went back to measuring the idle voltage for the electrolytic board which is the last item on the table here:

4fvOMiw.png


the one that they call indring current by the typo that you pointed out earlier.

now it is unchanging zero for TP2-TP4 which is channel R
and it is also zero across TP1/TP3 which is channel L but it does change. every few seconds it jumps to 20 mV to 30 mV and then it jumps back to Zero.

if you want i can take a video of this behavior.

the only difference from 2 days ago is that i saw some white smoke come out of something right after i meade the measurements that i told you last time and i failed to figure out where it came from. it was a little (due to a small componenet)
when i saw the brown color on FR101 i saw aha that was it but i guess not. it came from something that was close to the heatsinks. possibly on the lectrolytic board.
 
before i do that let me tell you something. i apologize if this will throw you off or just plain annoy you because it probably is due to my amateurishness but i went back to measuring the idle voltage for the electrolytic board which is the last item on the table here:

4fvOMiw.png


the one that they call indring current by the typo that you pointed out earlier.

now it is unchanging zero for TP2-TP4 which is channel R
and it is also zero across TP1/TP3 which is channel L but it does change. every few seconds it jumps to 20 mV to 30 mV and then it jumps back to Zero.

if you want i can take a video of this behavior.

the only difference from 2 days ago is that i saw some white smoke come out of something right after i meade the measurements that i told you last time and i failed to figure out where it came from. it was a little (due to a small componenet)
when i saw the brown color on FR101 i saw aha that was it but i guess not. it came from something that was close to the heatsinks. possibly on the lectrolytic board.
What is your geographic location ?
 
this is 3 minutes after powering on. the first few seconds after it turns on it was 50mV. also reminder that it is channel L the one that was behaving before. R is just zero now.
 
i gotta say i have nio idea why i asked my location or yopu want to see my multi meter. its like watching sherlock holmes at work haha

gBrVibq.jpg
 
Just wanted to check and see if you were on the DC volts function.:biggrin:
 
lol yeah i was on DC. not that i put being on AC bellow me. it is absolutely something id do. but not in this case
 
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