Overload Lamp on CR-1040

[rce107]

Finally!

After FedEx tried their best to destroy it, I put the icing on the cake by shorting the lamp line to ground. Blew the fuse and took out D701 on the P.S. board. After replacing the diode, I replaced all the lamps. Boy it looked great so it was time to check it out. Now the relay never clicks on and the overload lamp is on. After checking all the components in the protection circuit, I checked my power supply Vcc's and found no +50 or -50vdc. Traced back to power supply board and a regulator transistor that had developed hairline cracks in the solder connection. Now I know why they put epoxy on those two square heatsinks!
Works and sounds great now. Whew

 

[merrylander]

Good on you, as to the diode if it does the job, why worry?

 

[Vint Age]

I had a Yamaha C-6 shipped to me a couple of years back with regulators pins looking just like that and glued down tall heat sinks too. The pins would make contact until you'd walk into the room when all hell would break out.

I guess Yamaha wasn't expecting us to be shipping this gear around the planet 30 years later.

 

[Scudieri23]

I understand this thread is 13 years old now but this seems to be exactly what I'm dealing with. Shorted lamp circuit and blew the 2a fuse, an 80v 220uf capacitor and D701 diode. Replaced diode with 1N4002 and capacitor with a Nichicon gold -which is smaller than the old one I am trying to figure out a better replacement. But the heatsink on 701 transistor popped up from the board it's overheating. Power overload light is on. Rest of the diodes seem fine , not sure how to test transistor if this is my issue. New to diagnosing stereos and want to learn but also don't want to destroy this 1040 I love it.