The Workbench

Re: BM8000 beomaster standby only

Jeff Hoyt — Fri, 15 Jan 2010 20:52:31 GMT

I know this thread is so 2009, but I wanted to report in that this fixed (so far) a big problem with my BM8000. The wires went in pretty cleanly, and it looks no worse than some other "factory" circuit modifications I've seen!

Thank you, Peter and geearr, for the circuit information. And thank you, burantek, for pointing me to this thread.

Re: BM8000 beomaster standby only

burantek — Fri, 08 May 2009 13:05:39 GMT

...nearly 1 week into the fix and everything is still perfect!

Re: BM8000 beomaster standby only

geearr — Sat, 02 May 2009 00:18:01 GMT

Jeff

Thanks for the feedback. Very pleased to hear that it all worked out well for you. Now you have the BM8000 working, all of your other units will be put to one side.

Have fun and it is satisfying to know that I was able to help. That beer sounds good but it will be fairly expensive by the time that we meet!!

Regards

Geoff

Re: BM8000 beomaster standby only

burantek — Fri, 01 May 2009 23:19:42 GMT

gents,

my apologies... "midweek" ended up being this evening...

well, i turned on the bm4400 in the background, grabbed my granny glasses, and heated up the old soldering iron!

plugged the board back up, plugged it in, saw the standby light up, pressed P4 (my fav preset for some reason) and guess what?!?!

it worked!

the bm8000 has been brought back to life! it works now just as it was supposed to! i will play it over the weekend to see how things go, but preliminarily, well, what can i say?

i still have to sort the opto sensor for tuning (looking for one in the wanted section), but i just wanted to let you two know how delighted and grateful i am for your assistance! should our paths ever cross, the pints are on me!

i am happy to consider this matter closed (better not jinx myself)! let's see how the weekend goes...

regards,

Re: BM8000 beomaster standby only

burantek — Sun, 26 Apr 2009 21:22:48 GMT

peter and geoff,

many thanks, that pic cuts right to the chase!

(the previous one took me to a dealer login page)

i will report back asap, but i am very busy at present... hope to have the 8000 on the bench perhaps midweek???

regards,

Re: BM8000 beomaster standby only

Peter — Sun, 26 Apr 2009 10:30:01 GMT

Try this one. It only shows the ICs involved - not the whole PCB.

Re: BM8000 beomaster standby only

Peter — Sun, 26 Apr 2009 10:27:30 GMT

Works on my Firefox. I'll try doing something with it.

Re: BM8000 beomaster standby only

burantek — Sun, 26 Apr 2009 08:31:11 GMT

peter!

much obliged! but unfortunately, the pic seems corrupted???

i have tried a few browsers and no luck...

thanks so much,

Re: BM8000 beomaster standby only

Peter — Sun, 26 Apr 2009 02:48:30 GMT

Intermittent failures in module 9

Symptom:

Various intermittent failures in module 09.

Cause:

Poor solderings in through platings.

Solution:

Wires are mounted as a replacement of the through platings.
The wires are mounted from the following points (see diagram).

9IC4 pin 14 to 9R58 (arrows marked A)
9IC4 pin 15 to 9R54 (arrows marked B)
9IC4 pin 16 to 9R56 (arrows marked C)
9IC7 pin 10 to 9IC3 pin 13 (arrows marked D)
9IC7 pin 12 to 9IC3 pin 14 (arrows marked E)
9IC6 pin 10 to 9IC5 pin 4 (arrows marked F)

Furthermore the two points marked G in fig. 1 (9C17 - 9C18) are resoldered.

I think this could be helpful.

Re: BM8000 beomaster standby only

burantek — Sat, 25 Apr 2009 18:26:59 GMT

geearr:
Some of the symptoms that you have described seem to be very similar to those that was battling with last year. For example, I would set up the various frequencies in the STORE and within a few days they would become corrupted. Some of the pre-set channels reverted back to 87.5Mhz, some were lost altogether and the start-up volume gradually degraded down to zero.

remarkable!

when it decides to go off the preset... it always switches to P7 preset and display a frequency floating around 87.5!!! sometimes a bit higher... 87.6, 87.7, etc...

i had the schematics up earlier, and will now review in greater depth your suggestions...

sounds like we may have a winner! i really appreciate it!

Re: BM8000 beomaster standby only

geearr — Sat, 25 Apr 2009 18:16:14 GMT

Hi Jeff

Some of the symptoms that you have described seem to be very similar to those that was battling with last year. For example, I would set up the various frequencies in the STORE and within a few days they would become corrupted. Some of the pre-set channels reverted back to 87.5Mhz, some were lost altogether and the start-up volume gradually degraded down to zero.

I put out a question on Beoworld relating to problems with the BM8000 memory but received no feedback at all. Fortunately, I was able to talk to one of our local B&O techies and he told me that a long time ago, there had been a “fix” put out to help sort out some of the memory problems with this machine. Apparently B&O had recognised that there were some problems with the double sided board which houses the micro and had recommended a series of repairs to the through platings. Poor solder joints were causing intermittent problems in PCB9.

Late last year, I put some wire bridges across the following connections and lo and behold, I haven’t had any further problems since. The micro memory now behaves properly and all of the control functionality is good. The board now looks a bit tatty with all of those wires hanging around but it is covered by the lid so no-one will ever know. You could try and repair the following connections:

9IC4 pin 14 to 9R58

9IC4 pin 15 to 9R54

9IC4 pin 16 to 9R56

9IC7 pin 10 to 9IC3 pin 13

9IC7 pin 12 to 9IC3 pin 14

9IC6 pin 10 to 9IC5 pin 4

Resolder the terminals on C17 and C18

If you have a look at the schematic you will see the general area that is affected. There are also some other links around the micro that could be causing problems and I was ready to tackle those as well. Fortunately that work wasn’t needed.

As I say, this solution worked for me and it might help resolve some of your difficulties. Some of the relay chattering may also be caused by poor joints somewhere.

Hope this helps

Regards

Geoff

Re: BM8000 beomaster standby only

burantek — Sat, 25 Apr 2009 11:44:08 GMT

geoff,

thx for the reply! this has been slightly exasperating, but what a great piece!

here is what i can tell you...

1.) just rebooted, and this time it came right back to life (no .7 TP0 this time) -this readout comes up w/o any interaction from me, it just "appears" after a reboot... then i usually have to reboot again to get it back to life.

2.) when it is up and running, it is fantastic, seemingly no issues. if i standby it, and leave it say, overnight -it acts up again...

3.) thx for the monitor+standby test, i was not aware of it! after it came back to life, i tried it and received a successful: "TP"

4.) i have now noted some new sounds coming from the 8000 when it is running, sounds like "switching" like when going in and out of standby, it has also now started switching from the playing preset to another, but the frequency is incorrect for the preset "it" selected. when i return to the preset i was listening to, no frequency is displayed and no sound! arggh! (this has just started happening).

btw, all led displays are functional, none missing... i will open it up again and check the connections around the microcontroller. as i recall, it had a service sticker on it from around 1994... i will open it up right now!

i am thinking that there might be some issue w/ the relationship between the standby and running power sources and their respective switching???

thanks for the assistance,

Re: BM8000 beomaster standby only

geearr — Fri, 24 Apr 2009 17:35:05 GMT

I have a BM8000 which I rescued and that had a number of problems with the micro control which gave very strange behaviour. All turned out to be faulty connections on the micro board.

In your case, I am very confused by the display message that you are getting, .7 TP0? Have you been able to check to see if all of the display LEDs are working and is this message correct. It is fairly easy to probe all of the individual LEDs. If all of the LED's are functional, have you tried the micro test, pressing MONITOR and STANDBY together and getting the OK result of "TP"

I will be interested to follow your progress

Good luck

Geoff

Re: BM8000 beomaster standby only

burantek — Wed, 22 Apr 2009 15:54:41 GMT

update...

finally had an opportunity to get the 8000 buttoned up and placed. will live with the presets until i find the sensors.

at any rate, this thing is crazy!

i plug it in and nothing, back to standby. i replug it and it goes to .7 TP0, i replug it and it works great! run it a few hours -no problems. put in standby, select a source, works great. back to standby for the evening. then, next day... it repeats!!! replug after replug until i get it back on!

any thoughts?

Re: BM8000 beomaster standby only

burantek — Sun, 05 Apr 2009 13:29:58 GMT

ok strange!

had a cig, grabbed a screwdriver.

came back, and... now there is a display!?!?

it says:

.7 TP0

++++update++++

ok. got in. amazing for the general build quality that they did not use better connectors.

nearly all of the connectors were loose. a bit of fiddling and the control panel started working.

threw some p45's and an antenna on, viola! sound.

ok, now no tuning. the center board w/ the "stores" was ajar as well. clearly someone had been in before me as the backing tabs for the buttons had broken allowing the circuit board to push in freeing all of the buttons from their respective keepers.

i have that going back together right now w/ a little help from my second best friend, epoxy. time for a cig.

more later...

++++update++++

ok. "stores" board back together and installed. filtering and stores works fine now. back to the tuning problem.

i knew the volume side worked, so i started there. jumpered around until i could get the vol up and down w/o using the optics. tried same on the tuning side, and got it to move from 106.7 to 106.8 haha! the solders looked bad. clearly had been reheated in the past. reheated again, but no luck. so i manually "jumped" all my stations and stored the presets. i could go the "redneck" way and leave it as is, but it appears (bad pun) that the optics are bad on the tuner wheel pickup, and i would like it to be right.

anyone out there maybe have the optics board with leads attached? i am going to go ahead and replace both volume and tuning, so ideally i'd like to a find a pair. i would also entertain the entire push button panel with the leads attached.

at any rate it is running as is for now, and surprisingly the displays seem to be intact.