Little bit more about the 5500. I don't know  if this is common fault in 5500 series but RCA sockets in this amplifier were lose from the soldering points. I had to solder them back to the board.

It sure looked like no external damage just poor soldering job from beginning. I discovered it when plugin in my phone via tape 2 RCA sockets. Lucky for me that was very easy soldering job and didn't even have to take off the cover.

I just (hopefully) repaired another 6500. This Beomaster worked fine for a couple of hours, but if you then put it into standby, after an hour or two the standby dot would vanish and the Beomaster seemed dead. Leaving it unplugged from mains for some time usually gave another try.

I replaced the usual caps - see the first pages - and it seemed to work fine. I then disconnected it from mains to remove the probes I used for idle current adjustment (I don't do that "my probe slipped and I fried the device" stuff) , but it was dead again when I connected it back to mains. Not even the usual relay click (which actually means the amps are powered on - the Beomaster energizes the main relay when it goes to standby).

Some measuring around revealed missing standby power, just a little over a volt at the emitter of TR12. So no power to the CPU either. Turned out to be an intermittent standby power rectifier (D3). I replaced it and all seems fine again.

I'm posting this because my BM5500 had an intermittent D3 as well when I bought it years ago. Seems like a common fault.

Does anyone have parts to this card available, (processor, rom )? I have one with no life. Only some curious level pulse between processor and rom data line. Chrystal, voltages etc are ok.  Card is identical as yours only S/W is 1.4

The processor is a generic 8032 which should still be available; if not new, then NOS on some popular auction site (avoid the later "downward compatible" derivatives which have additional features, as they may not work properly with the B&O firmware). I guess the ROM could be easily replaced with a regular 27512 EPROM chip, but of course you would need to get the firmware from somewhere. I would be suprised to have a faulty ROM, but the CPU is a bit susceptible to ESD and overvoltage hazards from the external Datalink lines.

But first check carefully the reset circuitry, as the processor won't start up correctly if the RESET signal isn't driven properly when the power comes up. The PSEN and ALE lines should have a lot of clean logic level traffic at ~1 MHz when the CPU is running.

Hello all!

I have decided to replace some capacitors in my BeoMaster 7000 (module 9, the front circuit board with the display) as described in this thread.

I have measure the three of them with my ESR meter and one was dead, one had 5 times the resistance and the third was ok. I will be replacing all three.

Question 1:

The values I read from the components are:
C15:  1uF/100v (Question, I cannot find 100v anywhere, only 63v, will this be okay???) When i look at the service manual I am not sure how to read it. Is it mean that the voltage is 40v? Please see picture from service manual I have attached.

C20:  10uF/63v

C19:  2u2/63v 

Question 2:

Will I need to tune the IR receiver once I have replaced the capacitors as per this quote or was this due to a more complex issue being investigated?

Look at page 7 from the below service manual, that is where I took the clip from:

link

Many thanks all, I will report once I have completed the repair.

BeoMedia

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63V should be enough for C15. It sits on the unregulated 40V power supply line, and the filter cap for that line (in the power supply) is actually specified as 50V. 100V was probably just a convenient choice when the Beomaster was designed.

Don't touch the adjustments (I probably wouldn't have needed to either).

All three capacitors are now replaced and the system started up effortlessly from standby (so far so good). The repair went very easy and I have some pictures I can upload later if there is any interest.

However, trying to start it up from standby at a later time (i.e. after it has been connected to the mains for some time) it is again not very sensitive at all to receive an ir command like RADIO or similar. (I have even disconnected the aerial but it is the same issue.) Once it is turned on it is very sensitive to new ir commands and works as it should. The problem is only when trying to wake it from standby.

Are there other capacitors on a different circuit board I should be looking at as well? Should be likely as they are all equally old.

Any pointers would be much appreciated.

BeoMedia wrote:

However, trying to start it up from standby at a later time (i.e. after it has been connected to the mains for some time) it is again not very sensitive at all to receive an ir command like RADIO or similar. (I have even disconnected the aerial but it is the same issue.) Once it is turned on it is very sensitive to new ir commands and works as it should. The problem is only when trying to wake it from standby.

I have the same problem with Beomaster 6500. If I disconnect it from mains and replug it, it will work fine again - for some time. I would also be delighted if someone has clues where to look for...

Hello Mika and all on this thread,

I thought I would need to continue my work on my BeoMaster 7000. The issue I have had for some time now is that the BeoMaster 7000 is not very sensitive at all to an ir command when it is in stand by and has been connected to the mains for some time. (If it has just been connected to mains it is fine. Once it is powered up and playing it is also fine.)
I have looked at the capacitors on the power supply and power amp board as per Mika's brilliant tutorial on the first page of this thread and I will be looking at replacing these. I measured them with my ESR meter and all but one gave an acceptable value.

However, I am now also struggling with poor signal reception on the radio. I can hardly get a channel. So, I also looked at the caps Mika mentioned on his post concerning the radio circuit board. Here I also had poor caps according to my ESR.

Then I went on to measure other caps on the same radio circuit board and many of these were also out of spec!

Question: It seems to me that most caps on these systems are ripe for replacement. How should an amateur go about this? Shall I try to replace all caps that measure out of spec or only take one step at the time (for me it would probably be replace the caps on the power circuit board, then later move on to the caps Mika mentioned on the radio board).

Shall I leave the other out of spec caps be for the time being?

In theory it should not hurt to replace them all but I understand that the circuit boards are rather fragile and traces can easily lift from the board. 

Question: How do you guys repair a lifted trace? Are there any pens that can carry this sort of current or how do you save your boards once a trace has lifted? What is the best temperature to desolder caps with to avoid lifting traces perhaps 400 celcius?

Many thanks all! I really want my system back to full glory and I will happily be posting pictures and comments from what I have learnt along the way once I am done.

BeoMedia