ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello out there
I am working on my Beocenter 9000, and did a resolder of the decoder board, because there was no audio output from it. It was playing the disc without problems, but just no sound.
After disassembly, it suddenly cannot spin the disc. The spindle motor turns the disc clockwise a couple of degrees, and i hear an annoying accoustic noise from the spindlemotor or the focus system. The big relay on board 66 clicks a couple of times within 10-12 seconds, and the system goes back to standby.
Do you guys have any input on this. Im a bit confused. I have checked the soldering i made, and it looks quite good. Maybee the temperature from the soldering iron has forced the failure? But where should i start.
Everything else work perfect on my BC9000, and the linear regulators does not turn hot at all.
I have the servicemanual for Beocenter 9500, which is quite similar, but not in the cd section. My Beocenter 9000 is with the old CDM-2
regards
Thomas
The servo board is very sensitive to overheating. The copper tracks losen and break and the board delaminates.However, with decent tools and skills and a good ESD-safe workplace, I really can't point my finger toa specific component or circuit but the symptoms, you describe are those of a non-focus situation.This could be due to lack of laser power and/or electronical or mechanical lack of focus control.
The deck emits a laser beam to see if a CD has been loaded.The servo board will drive the laser lens in and out, closer and farther from the CD a couple of times to seek the focus point.If no response is received, it rotates the spindle a bit to place the laser beam on a different area of theCD surface (in case the first place was for some reason not suitable).If this also fails, the deck assumes that no CD has been loaded (and some players will then go into standby).
Some CDM versions have a ribbon cable running from the servo board to the laser block, around a sharp 90degcorner inside a plastic support where it easily breaks if accidentally or inadvertently pulled.It happens EASILY so never pull this cable !
Did you replace C2103 ? That's the filter cap for the laser output transistor.- If so, did you use a suitable component brand/type like f.e. a blue axial Philips like the original ?- If not, do it.
Martin