The Workbench

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

satmonster321 — Sat, 04 Jun 2011 06:28:57 GMT

Hello,

you can read my whole story about Beomaster 5500 in separate thread:

http://forum.beoworld.org/forums/t/39069.aspx

Regards

satmonster321

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

egoh — Tue, 12 Apr 2011 15:56:46 GMT

Thanks again satmonster321. I had the same stuff blow on my 4500. I replaced the 4 100uf caps and the 68 ohm resistor. Working great again, however, I'm going to replace all of these old caps once I have a little time.

FYI, if anyone need the cap number for the Beogram CD4500 check this thread:

http://forum.beoworld.org/forums/t/38713.aspx

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

egoh — Tue, 12 Apr 2011 14:17:29 GMT

Thanks for this thread. I have a similar problem with a Beogram CD 4500. Unfortunately, the service manual isn't available for my model. My 4500 also would only output white noise. I swapped the 100uf caps on the opamps as well. Got rid of the white noise, but now I have no output at all.

Still hunting, but thanks for all the info on your 5500.

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

satmonster321 — Thu, 17 Mar 2011 15:39:40 GMT

Hello,

I checked all other caps and changed power supply to 240V. Thanks for the tip. Now the CD player works SUPER !!! It reads all CDs and CDRs without problems. The sound is really good.

Now it is time to reactivate dead Beomaster 5500. No signs of life, I discovered the short circuited capacitor on the radio board. This damaged the Zener diode that was responsible for 5V -> voltage increased from 5V to 12 V -> the 1 A fuse that protects the processor on the processor board was broken. After replacement I measured the voltages for the processor. All are OK so the processor seems to be OK. But I am afraid that the LED controller MM5450 is damaged. Does somebody know how to test the display board in Beomaster 5500 ?

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

Die_Bogener — Fri, 11 Feb 2011 11:16:12 GMT

Yes, they become pretty warm, but not really hot.

Check also the other caps, the job is still not finished. There are still some more caps that need replacement.

But... you can change the power supply from 220V to 240V. There is a wire bridge direct on the board of the transformer. Just move it from 220 to 240, it is marked on the board. Then the powersupply and the black cooler metal keeps a little bit cooler ;)

Re: Beogram CD 5500 - no sound, noise only - SUCCESS

satmonster321 — Thu, 10 Feb 2011 15:45:32 GMT

Hello,

I successfully repaired my CD5500. Thanks a lot for the help !

What I did?

First I checked the ICs (IC2, IC2 and IC3) for the power supply->all voltage OK. Then the power of opamps IC11 and IC12. At pin 4 the voltage was 13,9V (OK) but at pin 8 there were some millivolts. Check at capacitor C102 and C202 showed, that both had short circuit. I decided to replace all capacitors that are used for power supply (C102, C202, C110, C210 and lot others). After capacitor replacement the voltage at pin 8 of IC11 ant IC12 increased to -4V (better but not good). Then I discovered that R101 (68 Ohm) had about 1MOhm. After replacement of the R101 the voltage at IC11 and IC12 at pin 4 and pin 8 was -14,7V and +14,7V. I decided to check the machine at my Beomaster and it PLAYED .

I have additional question: it is normal that the diodes D11, D12, D13 and D14 (really big diodes) are very hot during the play? I touched the board on top (diodes are underneath) and it was really hot.

Re: Beogram CD 5500 - no sound, noise only

Dillen — Mon, 07 Feb 2011 13:35:24 GMT

Also worth checking all cables, plugs and connectors.
I've also seen a couple of cases where the main board had breaks to the copper traces
near the front right side corner. One of them even had the corner broken clear off taking with it
5 or 6 copper traces.

Martin

Re: Beogram CD 5500 - no sound, noise only

satmonster321 — Mon, 07 Feb 2011 12:59:37 GMT

Thank you for quick response. Yes I have SM, but unfortunately no oscilloscope (still beginner...).

I will check the 5 V supply and the power of the opamps as you stated. Maybe I can discover something.

Regards

satmonster321

Re: Beogram CD 5500 - no sound, noise only

Die_Bogener — Mon, 07 Feb 2011 04:25:06 GMT

That's a little bit more difficult. You have the service manual and an oszilloscope?

Check wether the opamps have power and the sound signal is available.

It could be also the 5V supply, the CD5500-7000 has 2 of them. One of them tends to fail, killing the 4164 RAM chip.

Beogram CD 5500 - no sound, noise only - SUCCESS

satmonster321 — Sun, 06 Feb 2011 15:51:19 GMT

Hallo,

first I want to thanks all the people in the forum, who writes interesting tips regarding repair of the B&O stuff. I bought my first equipment one year ago (Beogram CD6500) and was able to repair it (servo capacitors) after researching in this forum

Now I own the second one, the Beogram CD5500. It had the same problems with finding the CD, so I fixed it exchanging the capacitors on the servo board. It reads the CDs without any problem. All service steps (1-4) are OK.

The problem is, that, if it is connected to my BM6500 I only can hear noise. All operations working fine (skip the track, pause, mute etc.) from remote or from the front panel. But no sound, noise only. Like from not adjusted radio.

Does anyone has an idea ? Thanks in advance !

One tip from me: the Beogram CD5500 player had problem with the CD tray. After some close and open operations it was slower and slower and finally it stoped the moving. I found out, that the soldering of power supply cables on the main board was broken. After new soldering the CD tray motor seems to have enough power to work properly (or the microprocessor, I don't know).

Regards

satmonster321