Beomaster problem after Recap

12 replies
H(
Offline
haptomai (archived2)
Bronze
Posted January 15, 2021 at 15:33 GMT
#2212691

Hi,

I have a Beomaster 1900 (Beomaster 1900-2 T2903), a friend gave me it with a pair of Beovox 2400. I would like to use it daily but there was a annoying "hum" at good volume. So I decided to change all the capacitors.

I bought the kit from beoparts-shop.com with all the caps needed.

Great, after a long time awaiting them, I finally found time to change all the 62 caps I found !

I made a quick test without all the panels and screws -> every tactile buttons worked (the phono was not working before, now it is), but no sound. I plugged an headset and then, I could only hear the radio when I pushed the volume to maximum. I though it could be a mass wire problem, so I put all the panels and screws.

Now I have a new problem: instantly after selecting a source, it goes to standby...

I check every caps polarity, sounds good, checked some wires, no one seems unsoldered.

 

More info: A service have already been made one time before I acquired it, all the 2.2uf have already been changed, but I replaced them. Also there is a strange part with long wires not in place (I guess it have been added by the person who serviced it long time ago). And I did not replaced the reservoir capacitor, not in the kit.

https://photos.app.goo.gl/s4bJZUPTtPaPRRSZ8

https://photos.app.goo.gl/jfNeEw4ZyrmM6zXy9

Could please help me find some things to test ? I only have a multimeter, no capacitor tester

Thx :) 

DI
Offline
Dillen
BronzeModeratorFounder
Posted January 15, 2021 at 15:53 GMT
#2212692

Check the solder joints at the output stage darlington transistors.
If they hang like in the photos, with heavy cooling fins, while you flipped over the board countless times, their solder joints will have broken.

In most cases, you can do a full recap to a Beomaster 1900/2400 without taking out the board.
Just losen corners or sides enough to work in there as you go.

Martin 

H(
Offline
haptomai (archived2)
Bronze
Posted January 15, 2021 at 16:15 GMT
#2212693

Ha, thought they were maintained firmly by screws. So I screwed up Erm..

Thx for the advise, I'll check that asap.

Full recap without taking the board out, damn if I knew that ! I tried to do as the picture shown in the kit. My bad

H(
Offline
haptomai (archived2)
Bronze
Posted January 15, 2021 at 16:15 GMT
#2212694

< this is a bug >

H(
Offline
haptomai (archived2)
Bronze
Posted January 15, 2021 at 16:15 GMT
#2212695

< this one too, sorry >

H(
Offline
haptomai (archived2)
Bronze
Posted January 15, 2021 at 17:31 GMT
#2212696

I just checked, seems ok for me:

Here is the link of the full album, I made photos of the soldering joints

https://photos.app.goo.gl/unwKkNJyh7KoAVZcA

I remove the front and back panels, and tested, I can select the source again, but still have problem with the sound really really really low.

 

Thx

JE
Offline
jesperb
Bronze
Posted January 16, 2021 at 09:20 GMT
#2212697

Maybe the 2 red Roederer caps in the volume section of the control board has something to do with this ? They should go as well. Don't buy big ones, then you won't be able to close the lid 😁

DI
Offline
Dillen
BronzeModeratorFounder
Posted January 16, 2021 at 10:01 GMT
#2212698

The shutdown is usually caused by DC present on an output. Cracked solder joints, shorted components etc.

Martin

H(
Offline
haptomai (archived2)
Bronze
Posted January 16, 2021 at 10:42 GMT
#2212699

Hi jesperb, 

 

I don't really understand what are the Roederer caps sorry, could you highlight them on a picture please? 

I should mention that the device was working "fine" before the recap 😅

H(
Offline
haptomai (archived2)
Bronze
Posted January 16, 2021 at 10:50 GMT
#2212700

Alright! I have great news: I'm stupid.

 

Haha, no but I forgot to plug a wire from the mother board to the control board (the one with three pins between Bass and Treble potentiometers).

Now the sound is higher (only tester on headset) but the sound is saturated all the time.

And the phono was not working again because the connecting pin was unsolderer. Resoldered it and it works again 👌

 

So: maybe there is a short-circuit somewhere 🤔

or
BeoWorld Gold Membership card
Join BeoWorld

Register to access the forums, reference material, and exclusive member benefits — including our monthly prize draw.

Become a Member

December 2026 Prize Draw

Gold Members Only

As a Gold member you're automatically entered into our exclusive prize draw — your chance to win iconic Bang & Olufsen products. A unique benefit of BeoWorld Gold membership, every draw brings a new opportunity to win something special.

View Prize Go For Gold