Sound cutting out, coming back after a few minutes Telefunken Hifi Studio 1 M

[dubout]

My current project is a Telefunken Hifi Studio 1 M with a faulty amplifier. After turning it on, the left side sounds distorted and somewhat 'brittle', mo matter if it is switched to radio, tape or aux. After a few minutes the sound normalises and it sounds like there has never been a problem. It seems when the components warm up the problem dissapears.

Has anyone experienced a similar problem and has an idea what component could be responsible for this behavior? What component comes back to life when warming up? Is it a capacitor or more likely a transistor etc.? Where should I start looking?

 

[hopey]

Sounds like a capacitor issue, does it perform the same on batteries? Try swapping the speakers it could be in the speaker coil.

 

[dubout]

Yes, it is the same with batteries. Swapping speakers didn't change a thing, too.

I have tried to find the component with freeze spray but wasn't too successful. Also while working on the pcb I produced a short and blew a fuse ... I replaced the fuse but since then the channel is completely silent. Stupid me. I will have to measure the old fashioned way.

I have put it away for now but your tip will be helpful when I start working on it again!

 

[hopey]

If you open it up and try to recreate the issue then touch the top of the small capacitors near the amp chip and it may create a buzzing noise then you found the faulty cap.

 

[dubout]

That's a very precise instruction, now I have to put it on the bench again ... Thanks!