Hi everyone,

Picked up a 1900 in a boot sale for £5, but there is a small problem with the touch switches. After the unit has warmed up, maybe 10-15 minutes, whatever channel is selected will automatically reset to FM3 within a second. 

I asume this is a well known fault and wonder if someone knows what component is likely to be the culprit?

Opened up the unit but could not see any visible mechanical fault.

Welcome to Beoworld !

Replace capacitors (a kit exists for this) and the board mounted rectifier.
I can supply the parts if you need.

Martin

Hi:

Do as Martin suggests... start with capacitors.

Rectifier may or may not need to be changed. Earlier units had an underated rectifier, later ones seem to have had that problem corrected.

This may solve all of your problems so start there.

If still not well check for integrity of transistors on the touch switches.

I struggled on a similar problem for a while until I discovered that the one "master switch" transistor was  (which turns on the whole until) was leaking.

After all this you should also replace all lightbulbs with exact replacements, but don't worry about this until you get everything working.

Derek

Thanks for the replies.

I was using the amp in a cold damp warehouse. Since bringing it home (dry centrally heated) to fix it, the fault has disappeared. 

Could cold and damp affect the touch switch circuit?

So lets see if the fault re-occurs. Then I'll have a go at the caps.

Regards,

Tony

Damp conditions can indeed affect the touch sensors.
There is a total of 15 lamps in your Beomaster. A lamp kit is also available.

Martin

So far the fault has not re-curred. But just in case, how much is the cap kit and the lamp kit?

Regards,

Tony

You have a PM. Check your inbox.

Martin