Beomaster 3400 Barn Find, worth restoring?

5 replies
DU
Offline
dudu_mec
Bronze
Posted May 29, 2016 at 15:16 GMT
#2251428

Hi all,

 

At a house clearance I came across a BM3400 in somewhat good cosmetic condition so I brought it home.

Opened it up and this was the scenario

 

 

 

Haven't turned it on as there are some loose connections on the transformer and there are bulbs missing and the tuning dial assembly is falling apart

Is it worth restoring? I can live without the tuning dial as I rarely listen to the radio, only records or CD

Does anyone have the service manual that can send me by PM?

 

Cheers,

 

Duarte

AR
Offline
argentas
Bronze
Posted May 30, 2016 at 16:17 GMT
#2251429

You don't see this quadraphonic model very often, so definitely worth restoring in my opinion...

There's a circuit diagram and user guide for the BM3400 on this site (you'll need to upgrade to at least silver membership to access these), and the service manual for the BM2000 would probably be useful too given it is what the BM3400 was based on.

Martin.

Location: Exeter, UK

DU
Offline
dudu_mec
Bronze
Posted June 3, 2016 at 21:59 GMT
#2251430

Already downloaded the schematics for the 3400 and the service manual for the 2000.

Nevertheless I could really use the service manual update for the 3400 as it perhaps has a parts list and circuitboard diagrams, which I find really handy.

Going to dig into the amp. starting with the power supply

The triac is toast. It is a 2N6342A so I need to find a replacement.

The thing is, that without the parts list don't know if it's the original one or if someone has already replaced it.

Cheers

 

AR
Offline
argentas
Bronze
Posted June 3, 2016 at 23:34 GMT
#2251431

dudu_mec wrote:
Nevertheless I could really use the service manual update for the 3400 as it perhaps has a parts list and circuitboard diagrams, which I find really handy.

I've just had a look through my boxes of paper service manuals and just as I was nearing the end of the last box and was about to give up, I have found a BM3400 supplement 🙂

I don't have time to scan it for you now as it is late, I'm going away for the weekend early tomorrow morning, and I'm yet to start packing my suitcase, but if you send me a pm with your email address I will scan it and send you a copy early next week...

In the meantime, I can confirm that part 0TRIAC1 is listed as a 2N6342A

The supplement contains schematics, a parts list, a list of testpoint voltages and some service tips and is in good condition so once scanned should be a lot easier to read than the schematic available on the site.

Kind Regards,

Martin.

 

 

 

 

Location: Exeter, UK

DU
Offline
dudu_mec
Bronze
Posted June 4, 2016 at 00:08 GMT
#2251432

Thanks a million Martin.

Already sent you PM.

I' start looking for a triac replacement then. And I have a gut feeling that the bridge rectifier is also gone...gonna have to surf to the deepest parte oficial the internet to find the datasheet for the B80C7500

Cheers

Duarte

Duarte

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