ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
My forays into the damaged BeoMaster 8000 documented in another thread have uncovered some non-standard wiring that is as-of yet unexplained. While I doubt anyone will be able to remotely decipher what this wiring does, I figured I'd post some details up anyway. I'm personally waaay out of my league here, but if anyone knowledgeable is interested, here goes:
The wiring in question connects an IC placed upside down on a vacant place on PC6, the power supply board, to a female RCA cable exiting the chassis by the RH speaker cables and to the microprocessor board via various connections.
- The IC is labeled, in part, HFE40106. The rest of the label is obscured by lacquer from the PCB that has stuck to it.
- Pins 1, 5,7,9,11,&13 are all connected together, along with the shield of the RCA jack. This is then all connected to the circuit board through an unused hole near the label "C26".
- Pins 2,6,8,10, & 12 are not connected to anything.
- Pin 3 is connected to the middle conductor in the RCA cable.
- Pin 4 is connected to the processor board (PC9) via an added white wire to the front/bottommost pin of the connector for the white harness that connects PC6 & PC9.
- Pin 14 is connected to R83 on the underside of the processor board (PC9) via a red wire.
The wire connected to the frontmost pin of the white harness has been cut, and an electronic device with three legs (sorry, no idea what it is) has been soldered to the ends of the cut wire. The third leg is connected to the dial below.
- An adjustment dial (like the ones to adjust voltage on the other boards) has been added. One side of the dial is connected to C5 on PC6, which seems to connect to pin 2 of the 4050B IC that is normally on PC6. The other side of this dial is connected to third leg of the device mentioned above.
A few photos to follow:
My guess? An external IR receiver? Crazy, but the closest I can come up with. Microphone input makes no sense with a BeoCord 8000 right next to it.
Tom
My two cents: why even bother? You insured it, it was damaged, make them buy you another one.
Let's see:
1.) Intellectual curiosity.
2.) Because it's there.
3.) In case it turns out to be something uber-cool, like the rare coffeemaker connection kit...
The transformer came loose and cracked the Power supply board in this unit when it was damaged, so if this unit is ever going to work again, it'll need a new board, and that'll mean either restoring the wiring to stock or adapting it to the new board. This unit is essentially worthless at this point because it would cost more to ship to anyone who could use the parts than the parts are worth, but it's still interesting.
HEF40106 is a hex schmitt trigger, so there's not that much intelligent it could do, and it won't have any analog role either. My guess is some kind of an external control input to do... something.
--mika
I think you are right about external remote control.It could be some sort of ersatz link adaptor.Looks too horrid to be official.Do you have a circuit for the BM8000.It's a super unit,I'd be inclined to remove this gubbins and return the cabling to as original.
I was presented with A bm4400 to repair some time ago.Inside were all sorts of relay's and bolt on little boards.The socket panel at the rear had been chopped about at too.The owner had no knowledge of these gizmo's having bought it at auction.He was only interested in using the amp with his cd player,so we never did work out what the other gubbins was for,praps something to do with disco operation(sacroligious indeed!)
Nick
Let's hope it isn't some sort of strobe-light controller!
Unless someone has a lead on a replacement power supply board here in North America, this unit seems to be destined for parts. What a shame!
just out of interest,why do you need to replace the panel?It does'nt seem to be damaged.Great piccies btw.
The panel that holds the tuning and volume knobs is bent, the wood on the front and right are damaged, the glass display cover is chipped, the heat sink and surround are bent, innumerable plastic clips and stays are broken, and the PC6 power supply board appears to be cracked in the corner nearest the transformer.
Whoops!Thats tragic for such a great piece of kit.They are getting rare now of course,but in time another should crop up,praps best to keep this one as a "spares ship"?
Nick.
Sad case. Still a good parts pool though.The processor board is quite sought after.I know that at least Chartz is looking for one.
Martin
Dillen: Sad case. Still a good parts pool though.The processor board is quite sought after.I know that at least Chartz is looking for one. Martin
Thank you Martin for mentioning it! What a memory!
Jacques