About 6 month ago I changed caps and lamps (kits from Martin), until one month ago it played OK, but then it started jumping channels when playing FM radio, it would play 1 hour on FM 1, and then suddenly change to FM 5, I thought it was caused by some micro black outs, we have here frequently, last week this got worse, it started changing channel after some 30 min. and when setting it back to the first selected channel it would change again after some 15 min.

Yesterday I turned it on again and it was playing about 5 min, then it turned of to standby, I turned it on again and after 2 min it went to standby again, one more time, turned on and it played only some 30 seconds and went to standby, now it has the standby light on, and nothing works, does not turn on with any selection.

When it was playing it did not get hot and there was no bad smells or sounds

Any ideas anyone

Check the board mounted rectifier near the fuse and C92.
Check the fuse holder for lose contact.
Check the solder joints on the output stage transistors.

Martin

Will do Martin, thank you

The "now its fixed - now its broke again" virus seems to be going around this summer. I have had a bit of it myself Soren.

Follow Martins directions, the last 3 2400's I have refurbished have all had the outputs resoldered. I seem to remember that your replaced the board rectifier already.

and once again look at solder joints and for cracked tracks.

Eugene:

The "now its fixed - now its broke again" virus seems to be going around this summer. I have had a bit of it myself Soren.

Follow Martins directions, the last 3 2400's I have refurbished have all had the outputs resoldered. I seem to remember that your replaced the board rectifier already.

and once again look at solder joints and for cracked tracks.

Good thing I didn't sell it, it was near, but I like it to much, and yes the rectifier was changed as of your instructions, so now its open it again and do a better job. In Beocentral they have a description of the same failure, and more or less what Martin and you tells me.

Thanks again

Eugene:

The "now its fixed - now its broke again" virus seems to be going around this summer. I have had a bit of it myself Soren.

Is there a cure or vaccination available?

Rich:

Is there a cure or vaccination available?

The cure is "do your work properly the first time" or hard US Dollars to pay for it.

Vaccination is until now, as for the BeoVirus, not available.

I'm still thinking about what I did wrong, or is it because of power line fluctations or because with new components other org. components got "tired". I will come back with descriptions, if its the last matter we have to change the components the first time we open the units, or from the beginning use Eugenes "do it all" technic

It will take some days before I open the BM again, first of all because I'm a covard and afraid of what I might find, second because of lac of time, third because my wife is laughing her but of. She will never get to chose fabric for my speakers

Søren Mexico:

She will never get to chose fabric for my speakers

As Mika has said in my defense, "A man has to do what a man has to do."

Got it up and running again, did as Martin told me, it was the F1 fuse, showed some 38 Ohms, and the cable bunch that passes near it I think was bad positioned and touching when the command board was mounted, cleaned the fuse clips and it turned on without problems, resoldered endstage transistors and fuse clips, connected and left it on for now one hour, will leave it on for 3-4 hours to be sure its stable.

Looks like this

Outstanding! 

One of these days I'll get back to my two non-working BM2400s.......

Rich:

Outstanding! 

One of these days I'll get back to my two non-working BM2400s.......

Do it Rich its wonderfull looking recievers, remember you can turn out the main board from the frame when changing caps and wont have to desolder all the cable connections

Søren Mexico:

Rich:

Outstanding! 

One of these days I'll get back to my two non-working BM2400s.......

Do it Rich its wonderfull looking recievers, remember you can turn out the main board from the frame when changing caps and wont have to desolder all the cable connections

 

Oh, I know...I have a third fully working BM2400 (with poor cosmetics ) out in the garage driving a pair of Beovox S40s (which were my first woofer refoam).  I also have a working BM1900 sitting on the shelf in need of a pair of speakers....

As I've stated before, I think I prefer the look of the 1900 to the 2400.

Didn't work, left it on for some 4 hours, and it turned of to standby, turned it on again checked 15 V supply, and endstage 12 MV, right endstage preset is very difficault to adjust jumps from 11.5 to 25-30 MV and is unstable when once adjusted, I knew it, as it was difficault to adjust last time I tried, but this time I have presets in stock, thanks to Martin. Good to know that the fault trigger works

So tomorrow, change preset for right and left channel, Will look in my "put everything in this box" if I have new clips for the fuse, and change these as well. I slaughtered a Panasonic plasma and I think there was some clips there.

QUESTION, I FOUND CAP C66 BEING 470 mF and in the scematics it is shown as 10 mF, can this be right ???

New presets, new clips and new C66 cap, testing now 3 hours and counting, no problems, will leave it on for 2 more hours and then check the voltages again and hopefully assamble the BM 2400 again.

Conclusion: Change the friggin presets when you change caps.

Well, didnt work, down again, changed main rectifier and the 2 big 5000 caps, TR 27, cleaned all output transistors and applied new heat paste, repaired main switch.

This model is without the voltage selector switch (US model), when I connect and turn on main switch I have 127 V in to the toroidal transformer, out to pin 9 and 10 i get 18 V AC (feeding the rectifier for 15 V DC circuit) in my opinion too much.

HELP

Søren Mexico:

Well, didnt work, down again, changed main rectifier and the 2 big 5000 caps, TR 27, cleaned all output transistors and applied new heat paste, repaired main switch.

This model is without the voltage selector switch (US model), when I connect and turn on main switch I have 127 V in to the toroidal transformer, out to pin 9 and 10 i get 18 V AC (feeding the rectifier for 15 V DC circuit) in my opinion too much.

HELP

Went to it again but still the same, today I had 117 V ac in  and to pin 9 and 10 I have 17,4 V ac, after the rectifier 22.8 V dc, no power to the 15 V adjustment trimmer. What to do, is the main transformer gone ???

No reason to think the transformer has failed Soren, everything looks about right. You need to check the components associated with regulation in the standby supply.

Søren Mexico:

is the main transformer gone ???

Definitely not. It wouldn't deliver 18V AC then

Søren Mexico:

after the rectifier 22.8 V dc

Higher than mentioned but shouldn't be a big deal. Probably TR27 gets warmer.

Søren Mexico:

no power to the 15 V adjustment trimmer.

Do you mean the collector of TR27 has no voltage? (TP16)?

Please check all voltages mentioned in the circuit diagram around TR27-TR29 & write them down here.

Maybe we can get you out of this

   Gunther

hemenex:

Please check all voltages mentioned in the circuit diagram around TR27-TR29 & write them down here.

I have the following V: TR27 B=22.05V, C=0.0V, E=22.5V.   TR28 B=22.5V, C=0.0V, E=0.0V.   TR 29 B=0.0V, C=22.5V, E=0.0V

As E TR28 and B TR27 are connected there must be an err on the voltages mentioned - either 22.05V or 0V.

Is there a short circuit from C TR27 (+15V stby) and GND?

check all 3 transistors (at least the C-B diode of TR27 seems ok)

hemenex:

As E TR28 and B TR27 are connected there must be an err on the voltages mentioned - either 22.05V or 0V.

Is there a short circuit from C TR27 (+15V stby) and GND?

check all 3 transistors (at least the C-B diode of TR27 seems ok)

One time more. TR27: B 21.7, C 0.0, E 22.3.  TR28: B 22.3, C 0.0, E 21.7, TR29: B 0.0, C 22.3, E 0.0.

TR27 C is short to GND ( 0.1 ohm)

Sorry the TR28 E I got mixed or missed somehow.

Disconnect C97 and see if the short still exists?

Step1:

Disconnect C97 and see if the short still exists?

Short still there, and C97 is out and OK

Next candidates: C71 & C47a...

would he not measure 81R Hemenex?