I posted a “general” question on Beomasters in regard to their service needs over time. After posting I noticed a distinct odor coming from my Beomaster 2400, smells like an electrical fire mixed with hot oil. Pungent and nasty.

The Beomaster 2400 plays well and all functions work correctly, but I wonder if this isn’t a clear sign of transistor or diode failure in progress?

I wanted to know if the smell would get worse under load and/or there would be distortion however the S45 speakers I have connected to this Beomaster can not handle the power of this unit due to issues with one of the woofers.

Any thoughts on this one?

Jeff

Jeff,

Sounds like too high idle current(s).
Replace the trimmers and adjust to factory specs.
Could also be the board mounted rectifier toasting. It's fairly low dimensioned
from the factory so I like to replace it with a somewhat more powerful type.
We can never rule out caps either.
- Or any combination of the above.

Martin

Martin,

My thought was to open the 2400 up and see if my nose can lead me to the problem. With such a strong odor I imagine the offending component will make itself known. Just my thought.

Jeff

Piaf:

Martin,

 

My thought was to open the 2400 up and see if my nose can lead me to the problem. With such a strong odor I imagine the offending component will make itself known. Just my thought.

 

Jeff

Not a bad idea, I have done the same myself and it has worked.

Craig

Jeff,

I would check the idle current trimmers. They don't go out of adjustment, they oxidize and can even fall apart physically. First signs of problems is unstability and intermittent faults, then bad smells, smoke and deformation of the plastic grill above the cooling fins. If a trimmers slider oxidize or lose its tension and thereby connection, the resistance of the trimmer goes high and that brings the idle current way up. This will toast the output stage emitter resistors and transistors in a matter of minutes and seconds.

The trimmers are cheap components, easily replaced and adjusted if you have a DC millivoltmeter. Do one channel at a time, starting with the (most) defective.

Martin

Hi Martin,

I ignored your previous suggestion about the trimmers not wanting to acknowledge that I have no idea what trimmers are.

So since I can no longer hide my ignorance, what are idle current trimmers? Where are they located? What do they look like? And what do I test for?

Thus far there are no intermittent faults as the 2400 does everything it is supposed to do: play music from all sources. The plastic panel above the cooling fins is fine, and the smell, which has diminished considerably, is coming from the center of the receiver, not from the back where the cooling fins are.

I had really hoped to find an over-heated component, or one leaking, but this is not the case…. yet.

I had played the 2400 for an extended period, well over an hour trying to find the source of the smell, but gave up when the odor began to go away.

So does it still sound like the trimmers and if so, directions please….

Thanks, as always.

Jeff

Just a quick update.

The Beomaster 2400 continued to play without the slightest problem and the odor slowly diminished.

As such Martin feels that it was likely dust collecting in a hot area and giving off the nasty smell.

Jeff