Hi Guys,I've had an issue with my BG8000 turning itself off when it's supposed to drop the tonearm. The arm moves into the correct position, you hear the muting relay click and the unit turns itself off. After a few seconds it comes back to life and the tonearm returns to its resting position. So I decided it needs a recap and a check of all those solder points....Tonight I got it on the bench and reflowed the solder on all the edge of board connectors and the processor connector. It's now dead... no standby light and no response to any of the buttons. The only sign of life is the light on the opto assembly is lit up. Any ideas?Lee
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Beogram 8000 dead
17 replies
Hi Lee,
In times like this you have to get back to basics. Start with the power and work your way to operations.
Open up the Beogram into service position. Check the power from the transformer to the rectifier and verify the DC voltages. You have to make sure nothing funny is going on with the power or else the processor won't function. The transformer assembly has a fuse inside it so it is possible that is blown.
I also have to ask if you checked the solder joints you re-soldered under magnification. Those Beogram PCBs have a lot of small solder pads and it would be very easy to have a short between a couple without realizing it.
Double check your recap work.
It would also be good if you can post several detailed pictures of the boards (component and trace sides).
-sonavor
Reading your original post again, since your Beogram opto assembly light illuminates then the transformer fuse must not be blown. Still, check the power supplies especially the +5 VDC to the processor. It sounds like the processor is not functioning now. If you changed the small electrolytic 47uF capacitor inside the processor housing, did you make sure the ground was connected to that correctly? That capacitor is a little tricky to get installed correctly.
-sonavor
So feeling confident after fixing the Beomaster 8000 and having lots of free time due to furlough I thought I’d revisit this Beogram 8000. I’ve checked all the connectors to the board and reflowed them. When testing for voltages I’m only getting 9v at c24 on the cpu board and around 1v at the cap in the processor can obviously way too low. And pointers? CheersLee
Difficult now. It's always easier to find problems with natural causes than to start with something that was already "got at".
You may have introduced one or more new problems, that, combined with the original fault, could make diagnosing more difficult.
Having said that, you may - or may not - have cured the original problem. Difficult to say.
That's why I usually recommend diagnosing and repairs before doing upgrades, blanket replacings or "once overs".
But check your work.
Check if you accidentally connected two pins by flowing them together.
Martin
Hi Martin,I’ve checked every single solder point that I’ve touched and can find no shorts. I’ve cleaned them all with isopropyl and looked under strong magnification. The only caps that I have changed are c27, the one on the regulator board and the two on the back of the main board.. The rest are all original. CheersLee
Did you make sure to solder the ground/negative side of C28 in the metal box with the microcomputer IC properly? That board is a little different as it has some solder pads on the component side.
-sonavor
Hi Sonavor,I haven’t replaced that cap yet. It’s still original and it looks ok from a soldering perspective. Login to view imageLee
Looks exploded to me...
And did you introduce the ground connection at C27, - the one that is lost when you take out C27?
Martin
I think that’s just a trick of the light Martin and the way the red wire is soldered on. The cap is definitely not exploded. Login to view imageAnd sorry I meant it’s c24 that has been changed. Not the larger c27 with the 3 pins. I think I’ve found an issue though...When I worked on this 3yrs ago I connected the shielding for the black wire that runs from the cpu board to the little “bodge board instead of the centre white cable. I’ve now rectified this but could this have blown a transistor?
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