Bemomaster 5500 shuts down after a few minutes

I have a used Beomaster 5500 and works fine until the unit warms up a bit and shuts down no matter if you are using FM, cassette, CD, or phono.  Amp will power back up immediately however the shut down comes quicker with each successive power cycle.  I have read through the forums and found a few notes about trimmers perhaps needing replacement.  I am electrical proficient but need instructions and help from a pro if possible.  

Nevermind I fixed it myself. :-)

Thanks for the information

No details?

I used the schematic to locate the two output trim pots and gave both left and right a half turn back and forth to renew the internal resistant setting location and returned to initial settings.  When I tested it afterwards, the problem solved.

Replace the trimmers, - they will fail again if not.  They are cheap and easily available.
And you definitely need to put a multimeter on the emitter resistors and set the idle currents per the manual.
Once you do, you will see, that the adjustments are quite sensitive, even very small movements will make a huge difference and you cannot
just "put them back where they were".
Too high idle and the output stage will overheat, too low and you will overload the tweeters even at lower volumes because of ultra high-pitched
harmonics from crossover distortion.
Keep in mind that this is a Class B amplifier.

Martin

Martin,

Thanks for the info and at this point I am selling the system so thanks anyways.

I have the exact same problem. Entire system has been stored in a closet for years, likely due to this issue. Turntable works great but it as well as the CD player & tape deck all come on & system shuts down. My daughter thought she could smell something electrical. Overheating? 

Could very well be the case. Silver members can download the service manuals and Martin (Dillen) can provide the needed parts and instructions to replace the trimmers, if you're handy with a soldering iron. If so, you might as well look to replace the capacitors too, since they don't age particularly well. Martin can provide those, too. Good luck!