Hello all
I'm new here, this is my first post.
I'm French so I'll be extra careful in my description as English is not always so easy for me.
I have an accuphase E203 that's behaving really strange.
One side is silent in stereo mode, no matter what input I use, while both speaker produce sound in mono mode.
This tells me the output amp is working properly (which is really good news!) but something is lost somewhere in the preamp section.
Every input has the same problem, both A and B speakers, so maybe the problem occurs where every input are mixed together but this is just a wild guess...
Could somebody please help figure out where to look first?
Cheers
François
I'm new here, this is my first post.
I'm French so I'll be extra careful in my description as English is not always so easy for me.
I have an accuphase E203 that's behaving really strange.
One side is silent in stereo mode, no matter what input I use, while both speaker produce sound in mono mode.
This tells me the output amp is working properly (which is really good news!) but something is lost somewhere in the preamp section.
Every input has the same problem, both A and B speakers, so maybe the problem occurs where every input are mixed together but this is just a wild guess...
Could somebody please help figure out where to look first?
Cheers
François
Then the problem is before the mono switch.
Start with cleaning all the switches and pots.
Especially look at the tape monitor switch, etc
https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU/ref=asc_df_B00006LVEU/
Start with cleaning all the switches and pots.
Especially look at the tape monitor switch, etc
https://www.amazon.com/Hosa-D5S-6-DeoxIT-Contact-Cleaner/dp/B00006LVEU/ref=asc_df_B00006LVEU/
That's what I did first, and it didn't change that mono/stereo problem.
It fixed the scratchy pots, though, which is good news!
It fixed the scratchy pots, though, which is good news!
Then all that is prior to the mono switch is the selector switch and the tape monitor switch, so look at those carefully.
Maybe there's a bad solder connection. Did you clean the input selector switch?
Maybe there's a bad solder connection. Did you clean the input selector switch?
I think I did clean all the rotary switches and pots, but maybe not enough!
I sprayed a lot of contact cleaner (KF F2) on (more like "under") the push-pull switches and along the shafts but I'm not sure the cleaner went all the way inside the switches.
If I use a signal generator and oscilloscope, are there measure points on the PCBs, or do I need to identify all the elements of the circuit in there and follow the signal paths with the probe?
I sprayed a lot of contact cleaner (KF F2) on (more like "under") the push-pull switches and along the shafts but I'm not sure the cleaner went all the way inside the switches.
If I use a signal generator and oscilloscope, are there measure points on the PCBs, or do I need to identify all the elements of the circuit in there and follow the signal paths with the probe?
First, I would try cleaning the input selector and tape monitor switches one more time.
Use the schematic to do signal tracing in the bad channel. Connect a signal to that channel.
Start at the driven input socket, and go forward, as little at a time, as you can.
When you lose signal, look just prior to that point. It should be before the mono switch.
Use the schematic to do signal tracing in the bad channel. Connect a signal to that channel.
Start at the driven input socket, and go forward, as little at a time, as you can.
When you lose signal, look just prior to that point. It should be before the mono switch.
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