Electronics > Repair
Yamaha M-70 massive damage
(1/1)
czarlz:
Not quite sure what happened here! For sure the fuse did not have a chance to say a word.

Have you ever seen parts (PCBs) for M-70? Those PCBs are so damaged that I would have to make them from scratch.
Swake:
Well.... thanks to some material regulations the house did not burn down. The other good news is that the PCB's still seem to be in a good enough shape that you can copy them. Hope you have a schematic, because whatever that black blob was before it is not going to be easy to identify.
amyk:
Lightning strike?

Schematics, service manual are easily found online. It's not a complex circuit. Whether it's worth repairing (restoring?) and parts availability is a different question.
Gyro:
It looks as if it's a big PIO (Paper In Oil) capacitor in the power supply mains filter... and they have a reputation for blowing up in 230/240V supply regions...

https://www.audiokarma.org/forums/index.php?threads/yamaha-a-760-a-760ii-a-960-a-960ii-a-1060-m-50-m-70-and-b-6-220-240v-warning.154682/

It sounds a bit like a massive Rifa PME on steroids - with added oil and probably not hermetic.


EDIT: From the service manual, it looks like C607, 470nF 250V, across the line, maybe it is an ordinary Rifa PME X Cap, difficult to judge the size and shape now. It looks as if that whole assembly is a Triac phase control regulator feeding the mains transformer primary. Yuk!
Navigation
Message Index
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod