I sent you an email.

John

Thanks John for your input

It seems I just solved my problem... This morning, when I woke up, I tried to launch the test program by pressing "Monitor" and "Standby" at the same time, as described in the service manual. I got TE 12, which points to a defect 9IC4 or a short Ic pin to chassis (pins 14, 15, 16, 17, 18, 19, 20.)

I was suspecting pin 16 since it's related to the activation of the +-55V rails. I thought, maybe that the solder blob created by inserting the jumpers was touching the back of the metallic cover placed above the components, on the back of PC9.

You can see these solder blobs here, circled in orange :

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I removed the bottom can and got back every functions! I replaced this can but I've let more room so it's not touching anything inside. It means that with time, the heat and cold probably displaced the cover somewhat, or bent the PC board, leading to this intermittent problem.

It was not that bad after all. I hope i'll be out of problems for a reasonable time now!

Guillaume

 

Good troubleshooting work Guillaume. So many problems have with this Beomaster end up being a connection problem.  Either some unwanted ground somewhere or some signal not making contact. That was a nice deduction and fix.

John

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Thanks,

I'm happy I got it back to work. I spent so much time on the whole set back then, I couldn't stand at the idea of keeping them only as pieces of furniture, nor at the idea of swapping the BM8000 for another receiver.

However, I perceive the 8000 set as one that could give up at any time : It always surprises me how beautiful the package is, but how nightmarish and compact the electronics fits in. I'm super picky when using it, I always switch off the power bar when it's not in use (I use it only during the weekend) I never go above 4.0... It's like as if I'm not confident about it.

My everyday system is composed of Beomaster 2400, Beogram 4002 and Beovox S45-2 : now this one is always on standby mode, ready to do anything : I'm super confident about it.

But getting back to the 8000 system is always a pleasure and it's indeed a fabulous set... only when there's nothing wrong!

Guillaume

 

Guillaume,
Is your Beomaster 8000 microcomputer board rear cover missing the paper insulator?

The rear, metal cover should have an insulator on the inside to prevent anything on the trace side from shorting.

 

Hi John,

No, there wasn't! I was not aware of that. Perhaps it was removed when the jumpers were added in the past. After i've put back the cover yesterday, I had another case of this short so I added a piece of elecric tape, under the cover, right above this location. This original solution, however, seems to be more elegant though!

That is one problem with a lot of used audio gear.  You don't know the history and odds and ends may have been removed and lost.  One common thing on the Beomaster 8000 are the three flat, metal springs under the release rail (the black metal bar you press to open the tone & filter controls).  Almost every Beomaster 8000 I have come across in the last three years was missing at least one of those springs.

John