Mods, I am not sure if this is the right section, where to post, please move to an appropriate area.
My Beocenter 9000 has a problem with the lights on the lower display. It started by the lights being a bit dimmer, at times, and it differed with seasons. In winter when it was cooler, but the indoor air was dryer they worked well, but in summer when it was humid they did not.
Now they do not work at all except for the "Clock" light if the power was removed, and the "Standby" light.
Other than that the keyboard works fine. Touching the appropriate area performs the function needed.
I ordered a used lower keyboard part consisting of 3 PCBs, but after replacing it I still have the same problem. I am told the new part is functioning and it displays the exact same symptoms, so doubt that it is also defective.
Searching the web returns no results for this problem. Does someone, here, know what wold be the next step in diagnosing this?
Check for cracked solder joints at the voltage regulator and filter capacitors.
Martin
Thanks. Is that at the power supply, somewhere, or on one of the 3 keyboard PCBs?
In the power supply.That's where the filtering and voltage regulator circuits are.
You can also check for correct voltage supply and amount of ripple to the display boards with a scope.