Hello everyone,
I just acquired a Yamaha M-50 stuck in protection mode. Here is what I have found so far. No burnt components on all boards.
Tested DC Voltage on the output transistors on both sides of the board per the service manual and seem to test fine.I plan on
removing output transistors from the unit just to verify that they are functional. Has anyone in this group had to pleasure of working
on one of these units?
Thanks,
Audi2014
I just acquired a Yamaha M-50 stuck in protection mode. Here is what I have found so far. No burnt components on all boards.
Tested DC Voltage on the output transistors on both sides of the board per the service manual and seem to test fine.I plan on
removing output transistors from the unit just to verify that they are functional. Has anyone in this group had to pleasure of working
on one of these units?
Thanks,
Audi2014
Me, but ages ago and my memory has faded.
Nice sounding amps and a very cool front.
In general I would check for worn solder joints.
Look for DC before the relay and compare with the other channel, if that still works.
I'll have a look at the manual for I don't remember if each channel has his own protection circuit.
Can you post the Service Manual?
Hugo
Nice sounding amps and a very cool front.
In general I would check for worn solder joints.
Look for DC before the relay and compare with the other channel, if that still works.
I'll have a look at the manual for I don't remember if each channel has his own protection circuit.
Can you post the Service Manual?
Hugo
Why would you do that?
It would be wiser to measure DC on the amplifier output (before the relays) and also power rail voltages for a start.
There may be fault in the amplifier but also the speaker protection circuit may give you false alarms.
Replacing all lytics in the speaker protection circuit would also not hurt.
Thanks, I advice to read it before attempting the repair.
Also, as madis said, no need to take the outputs out.
Hugo
Also, as madis said, no need to take the outputs out.
Hugo
Pages are missing in the manual.
Here's a better one:
Edit: Audi2014, I took the freedom to remove yours to avoid confusion.
Hugo
Here's a better one:
Edit: Audi2014, I took the freedom to remove yours to avoid confusion.
Hugo