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ARCHIVED FORUM -- March 2012 to February 2022
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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022

 

Beogram CDX On the operating table.

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Bellecycle
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Bellecycle Posted: Tue, Feb 2 2021 2:48 PM

Actual I have two in pieces unfortunate as one of them was working before I started.

No1 (was working) is I think a 1990s version with PCB boards are in good condition,  I changed the electrolytic  caps all correct orientation then I just checked cap 2466 on the power supply. What gets me is I marked the +  spot and still put it back in the wrong position. This blew diodes on the power supply, 6467, 6468 and 6459.  The critical moment was after the cd directory had been read, the 200mA fuse blew just as the first song started. Now I have everything apparently working except, rough sound can only just be heard when the volume is turn way up.

When a disc is playing  I have the following bad voltage values on the two NE5532N chips.

Pin 1 0v,  Pin 5 0v, Pin 6 0v Pin 7 0v.

For both  DAC chips

Pin 4 4v, Pin 10 8v Pin 11 8v  Pin 15 0v Pin 16 0v Pin 17 0v.

The SM voltage values I have for the DACs Show pin 4 3.5v  10,11 I think are both 16.8v  and Pins 15-17 are 9.1v 9.8v and 9.7v.

Everything else appears to be normal upto the DAC chips, so should I suspect the DAC SMDs ? I did see white discolouring around  resistor 3590.

 

N0 2 CDX this was dead, it now runs but the boards are not the best. Both boards have repaired module stickers. I know the decoder board has a fault, something is preventing the cd directory from being read. It spins at two different speeds for a few seconds then stops, any ideas?

 

Any suggestions on how to test the CDX in play mode. I have mine standing on the back  heat sink with the bottom off. I am I right in assuming the top part of the cd clamp is glued on to the lid?

Thanks, my hair is going greyer by the second.

 

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