Marantz SR-48mk2 Receiver - Power cycles off and on

[mstap42]

Greetings,

Someone gave me a Marantz SR-48mk2 receiver. A protection relay or something had begun cycling the power off and back on in shorter and shorter intervals until it finally stayed off. Idk whether it is the power protection or speakers protection.

A respected local electronics repair shop was not able to reproduce the problem, so I asked them to recap the power supply and signal path. For the next couple of weeks, they ran it as their bench stereo with no issues. I observed it working there and took it home.

At home, it worked for a few days, then the power issue started again. I took it back to the shop and observed it functioning normally as before. Back home, it was ok for another day or two. Ever since, it has been as first described.

The shop suggested dirty mains power as a possible cause. I tested with a borrowed a PowerLink Ultra power conditioner ... no luck.

Any ideas? I am reluctant to throw any more $$ at this modest value unit, but I would use for bedroom a/v or similar if it worked.

Thanks!

 

[painttoad]

i had something kinda similar on a luxman. it had bad solder joints where the ac mains came to the secondary transformer.

i know nothing about your unit but glanced at the schematic and it does have a secondary transformer and a relay for mains power but it's all on the same board as the power supply.

i would HOPE that the shop that recapped that power supply would have taken care of any poor solder joints but some shops are just shady and do the barest of minimum.

i can't really help anymore than to tell you to inspect the power supply where they didn't replace caps and look at the solder joints or you can post up quality pics here and we can put our collective eyes on it.

good luck.

 

[mstap42]

Appreciate it, thanks. Maybe it will be as simple as that. I will open it up when I can and post some pics.