Re: BeoCenter 9500 CDM4 doesn't spin up CDM2

yachadm — Mon, 21 Nov 2011 07:22:46 GMT

And this is the CDM2 which I connected to Decoder PCB 31 to confirm that that the Decoder PCB 31 was functioning fine after restoration

BeoCenter 9500 CDM4 doesn't spin up CDM2

yachadm — Mon, 21 Nov 2011 07:17:15 GMT

I have a BC9500 with a CDM4-33 (with Hall IC Turntable-Motor) in for restoration.

The customer complains that the CD motor does not spin.

I replaced caps on the Decoder PCB 31, and that is confirmed OK and functioning, tested in another machine (with a CDM2).

On the Servo PCB 30 (with both Laser Current and Focus Offset potis), I replaced all caps, including C2103 (ESR measured 91 ohms!), with Vishay AML138 series.

As per the SM, I set the R3105-3106 to 1KOhm, and then set the DMM probes on R3102. I connected AC, and the turntable rotated only a couple of degrees and stopped. Laser current voltage measures 1mV, and does not change with poti adjustment.

So, I presume that the laser is shot. Below is a pic of the CDM4-33 laser, and below that is a pic of a CDM2-10 laser. They look almost identical.

That part of the CDM4-33 laser does not look at all like the common CDM4-19 lasers available on ebay.

Does anyone have any pointers on which laser to buy to suit the Servo PCB30, or I could even take a CDM2 PCB (with Laser current poti only) + CDM2 laser to replace the original CDM4 here.

And, is there anywhere else I should troubleshoot on the Servo PCB 30 BEFORE connecting a brand-new expensive replacement laser?

This is the first time I have not been able to rescue the laser on a BeoCenter (always a first time!), so for those of you with more experience than me in this area, I'd appreciate assistance.

Additionally, for whomever is reading this - don't wait until your BeoCenter 8000-9500 fails - get the cap replacement done now, and prevent catastrophic failure like on this one.

Menahem

The Workbench

Re: BeoCenter 9500 CDM4 doesn't spin up CDM2

BeoCenter 9500 CDM4 doesn't spin up CDM2