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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

 

Beomaster 2400 failure

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Struer
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Struer Posted: Wed, Jul 8 2020 2:15 PM

Hi I recently acquitted a Beomaster 2400, but  when I plugged it in the two large grey resisters on the Right channel beside the heat sinks smoked and totally cracked. I turned it off.

The system is now understandably stuck on standby.

Any known culprits that might create this problem?

 

Kind regards,

Struer

Dillen
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Copenhagen / Denmark
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Dillen replied on Wed, Jul 8 2020 2:35 PM

Yes, bad idle current trimmers.
The idle was too high and the emitter resistors burned.
Replace the resistors and the trimmer.
Check the output stage darlington transistors, replace the pair if one has shorted.
Check the standby power supply.
Center the new trimmer and adjust it right after powering up again.

Martin

Struer
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Thanks for this. 

I only have a few replacement trimmers at the moment. Would it be ok to replace the trimmers near the burnt resisters for now?

Also does it appear that a previous owner has altered the board, or is this factory default?

 

Kind regards,

Struer 

 

 

Struer
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sonavor
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If the corresponding other side of the board has this (highlighted small board) then it is a modification B&O did.

Struer
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You’re correct indeed. So It must be for the ultrasonic remote signal?

sonavor
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sonavor replied on Wed, Jul 8 2020 7:03 PM

It is part of the preamplifier source selection/signal routing I believe. I don't have one open where I can check it.

-sonavor

Struer
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Hi, i am finding it quite difficult to source the large resistors on the R256/ R257?

Any ideas of where to find them or an equivalent?

Also do you still have light bulb kits available?

(I do need to solve the resistor problem first)

Kind regards

 

Dillen
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Dillen replied on Sun, Jul 26 2020 5:16 PM

Not sure about the resistors - I will have to check that when I get home,
but capacitor kit, lamp kit, potentiometer repair kit and even new correct rubber feet, yes.
PM or email me.

Martin

Beo_Jean
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Beo_Jean replied on Sun, Jul 26 2020 5:42 PM

Oh my!

ERO red capacitor nest here...  While you're there, you should change them also...

Dillen
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Dillen replied on Sun, Jul 26 2020 6:48 PM

Beo_Jean:

Oh my!

ERO red capacitor nest here...  While you're there, you should change them also...

The kit takes care of them too.

Martin 

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