[hcraig244]

Powered up via the variac and all is well, no smell of burning or sudden cracking of blowing fuses….hooked up to a BM4400

[hcraig244]

However the dust cover looks like some work has been carried out, this will require some attention…

The wood trim looks in good shape with all corners still sharp and clean

Overall the unit looks in good shape mechanically, and mostly cosmetically too.

A test run will determine if there are any issues functionally..

[hcraig244]

The BG4000 looks in very good condition internally with no signs of previous repairs…always a good sign

not sure about the quality of that image, but all looks well inside

Carriage drive belt is a bit out of alignment, not a problem.

[hcraig244]

Just had a look in my cannibalised BM4000 and it there is a volume slider still in there, looking at the manuals in here it looks like the 4000 slider is 20k and not 10k……however the manual for the 4400 also shows the slider to be 2ok…..i could desolder it and send it to you at cost if you can confirm your requirements?

Craig

[hcraig244]

Do you have an oscilloscope and a signal generator? I find those two pieces very useful when trouble shooting…..injecting a known signal and tracing it through would bring you to the offending component

Craig

 

[hcraig244]

New one on me…..not came across this before, does sound like a overheating issue….possibly breakdown of the compound applied to the output transistors on the offending channel not providing a good transfer of heat to the main heatsink? I will look forward to the conclusion of this one ;¬)

Craig

 

[hcraig244]

Ahh……well, thereby hangs a tale….when I was in the “4400” phase of my addiction I would buy any lost cause that appeared on ebay. I got a lot of pleasure from the repair and restoration of these units and chronicling the progress in the workbench forum of the old site, always received a huge amount of support and advice from the other members. The unit above came to me totally trashed and was described as “requires attention” which made me smile. The electronic repairs to the unit went well but the case ends and top where beyond reasonable repair and had to be completely rebuilt, never having attempted such work I decided to use a “ash burlwood” veneer on top of plywood…..it’s not a perfect finish but I like it. As a result, and unlike most of the others I acquired at that time, I’ve kept it…..

[hcraig244]

Ive still got a couple of these, please don’t ask me why two, and as can be seen both leave ventilation space beyond the cooling fins and into the power amp section….so I would say yours is normal ;¬)

[hcraig244]

Looking in the manual posted it doesn’t detail the cord arrangements for the unit, if you require any pictures let me know and I will post some in here…..I read the description in the products section or the 4400 and the mention of the 4401 which was described as having almost mythical status….this is a picture I posted 10yrs ago showing a 4400 I was restoring back then alongside a 4401 which was loaned to me for a while for a comparison between the two by founder member Peter…..who still posts here occasionally.

Peter knows of two that exist…..this one and another which may have been sold to someone in Portugal as I recall.

[hcraig244]

Unfortunately powering up isn’t an option untill a proper investigation is carried out, check all fuses (im suspecting blown ones) and power up with the variac whilst measuring the voltages at this regulator…..sadly not got the time right now so not able to provide the information you require….sorry

Craig

[hcraig244]

A look underneath reveals more potential horrors……

[hcraig244]

Dusting out has revealed a probem in the 15v power supply, someone has been here before me and wielded a soldering iron, the smoothing cap that has been replaced has a loose leg!

 

[hcraig244]

took it outside and let it go….hope it doesn’t come back into the house! will have a bit of a clean in here and make sure it all looks well before powering up…..i suspect it wont come to life or I wouldn’t have acquired it.

[hcraig244]

Look at this bad boy….

[hcraig244]

looking inside i discovered I was not alone in there…

[hcraig244]

found this in the bowels of the workshop, suspected I had one but wasn’t sure…dont even remember acquiring it to be honest!

looks a little sorry for itself…i think I must have bought it several years ago and not got around to it

[hcraig244]

I think I have a 3000-2 floating around somewhere…..i’ll have a look for it and if i find it i will take some measurements for you, you’ll need to be specific which points to measure

Craig

 

[hcraig244]

I thought there was a manual in  the products section for the 4400….however when I look I can no longer find it? as I recall it gives the details required to replace the tuner string, I think I have one somewhere and will have a look for you.

Craig

[hcraig244]

Progress…..I have also found a number of instances where the circuit diagram has been in error….I always take pictures of the units I work on before disconnecting or replacing items, I have also found instances where the actual markings on the PCB have been wrong.

You should replace all of those skeleton trimmers as soon as possible…if they let go you can blow your output transistors…and after all these years they are quite fragile…encapsulated trimmers are easy to obtain…a good idea would have been the purchase of a kit from dillen which contains all the recommended replacement components ;¬)

Craig

[hcraig244]

Check out these two links….there are a couple of different designs….

http://beolover.blogspot.com/2016/02/beogram-4000-replacing-broken-mmc-mount-with-3D-printed-replacement.html

https://beolover.blogspot.com/2020/08/beogram-4000-mmc-cartridge-mount-replacement.html

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