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

 

Beolab 2000 Power Problem

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Guy
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Guy Posted: Thu, May 17 2012 8:44 PM

A friend of mine has asked me to fix his BL2000.  He described the fault as an intermitent power problem and thought it was a loose wire in the mains connector.

I got the BL2000 earlier today and couldn't get any lights to show despite trying various power leads.  I therefore stripped it down and checked a few internal voltages.

I found that the transformer primaries were getting the full 230V, but that the secondary is only showing 19.4VAC rather than the 30VAC listed in the service manual.  Also the PCB1 dc voltage was only reading 4V, rather than 5 as required.

Do the transformers often go wrong - I couldn't see anything obviously wrong with the winding connections?  Any help would be much appreciated!

zvereczi
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zvereczi replied on Mon, May 19 2014 11:57 PM

Hi,

I also have a faulty Beolab 2000 (MK1) which doesn't show any sign of life (stand-by led doesn't light up either), so opened it... All fuses are ok in there. I'm also measuring 20VAC at the transformer instead of the 30VAC of the manual. Unfortunately checking further I have 0 instead of the 5VDC at the test connections, also no 9V. Realised that IC13, which is the switch mode power supply responsible for 5V is getting quite hot in a minute. Looks like the sign of damaged IC13, but would be nice if someone can confirm I should replace IC13 or check anything else causing problems, as I'm worried IC13 might not be the only problem in there... Any help or suggestion is also appreciated.

Additionally like to ask if it's normal to miss PCB8 (ML data transceiver)? Really looks like it's factory excluded, as even P20 connector on PCB1 is not present and the holes of the screws to mount the PCB have no threads inside either...

zvereczi
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zvereczi replied on Tue, May 20 2014 2:44 AM

I accidentally found info about the 20VAC and also about the missing PCB8 in the corrections of the service manual here: http://www.stabilgrus.dk/lab.pdf . I have an original service manual, but missing these corrections:

Page 8 (8-7 CORRECTIONS): The AC voltage on the transformer connection 1P2 pin 1 and 3 is approximately 20V AC.

So 20V AC is ok.

 

Page 2 (8-1 NEW FUNCTIONS): Software 1.1 has been changed to introduce option 5, introduced from serial no. 12620782.

If the software (PCB1) is changed in a Beolab 2000 with a serial no. lower than 11825160, PCB8 must be removed...

Well, mine has serial no. 14158357 and SW 1.1 - so I guess there was no need for PCB8 anymore...

 

Regards, Zoltan

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