Hi!
I bought a BC7700 some time ago, but I only yesterday found some time to work on it. It came with the MCP7700, a pristine SC77 and a couple of RL60s, all for about 90 euros. The speakers are in really good condition look-wise. I haven't had time to open them up, but a rattle suggests at least the ABRs need fixing.

I started cleaning the BC7700 (not thuroughly, yet, just get most of the dust and other other crap off it) and testing it a bit.
It seems to work pretty well. Obviously the tape deck needs new belts (they are still intact but so enlarged that they were lying on the bottom of the machine. :-) )

The part of the hinge for the programming lid (the one that is slid into the alu plate, I believe it is 2038 - "Friction plate" in the service manual) is cracked and needs replacing. Would anyone have a spare?

By just looking at the caps I can't see anyone obvioulsy cracked, but I guess they will need replacing anyway.

When playing (any source) the right speaker comes and goes. It appears that by increasing the volume it comes back, but that could also just be a random coincidence. Also I found that adjusting balance may make it come back, but again could just be coincidence. Turning off, and then on again, the speakers by pressing "Speaker 1" button in the programming section also seem to have some effect in bringing back the right speaker, but I wouldn't say it consistently works. Oh, and speakers 2 show the same behavior.

I should also mention that pressing "Mute" mutes the speakers but not entirely, very low volume is still coming out.

I've been reading (probably every post regardning the BC7700 and other systems) on the forum, but I couldn't find one with my particular issues.

Anyone have any ideas?

Thanks!
/  Johan 

Might be a cap issue but it could be as simple as dirty speaker din sockets of the speaker dins themselves.

Does the channel cut in and out or is it a situation where the sound is fading in an out ?

Hi Eugene!
I did spray the sockets and gave them a good rub with the male dins (also the ones instide the BC).. didn't help.
Of course I checked my cables too. Also, since they seem to come back without me actually touching the cables/connections it feels like it should be something else.

I'd say its more cut in and out than fading.
/  Johan

Johan:

Hi Eugene!
I did spray the sockets and gave them a good rub with the male dins (also the ones instide the BC).. didn't help.
Of course I checked my cables too. Also, since they seem to come back without me actually touching the cables/connections it feels like it should be something else.

I'd say its more cut in and out than fading.
/  Johan

 

Ok - as you can see from the two photos I have my output stage and preamp stage pictured before I recapped. While it doesnt show any physical leaks or cracks - what I did find when I removed the caps was some leaking on the underside of about 5 or 6 caps scattered throughout the set. I seem to remeber I had about 3 or 4 of the bipolars that were leaking underneath.

The other stupid question I have to ask is have you switch the speakers back and forth between right and left channels.

Ok, I believe you! :-)
I just wanted to see if anyone had other ideas as well.
The caps will be replaced.

Thanks!
/  Johan 

Johan:

Ok, I believe you! :-)
I just wanted to see if anyone had other ideas as well.
The caps will be replaced.

Thanks!
/  Johan 

they will be along soon enough Johan to add their input as well. Just to let you know, you  can buy a kit to include all the caps the cassette belts and the indicator lamps for your Beocenter from Beoworld member Dillen. He can also repair the ABR's in the Redlines as well.

Seems I replied to the wrong topic, sorry!

Thanks Eugene.
Dillen actually sent me a PM suggesting that it might be the male dins inside the machine that had bad solderings. I connected the speakers directly to the female dins inside, and sure enough, they both worked. So I figured I'd give it a shot. I desoldered the two dins and soldered them back in. I also used a little hot glue to fix the dins to the PCB, just to give them a bit more strength. After that, testing and putting it all back together the BC plays beutifully on both chanels.

Would you believe, it seems Martin was right! :-)

I'm really happy to have that one sorted out.

I still need to get the hinge fixed on the programming section lid. I took the whole thing out while I was in there, and it appears both parts of the hinge (the one that slides into the alu plate, and the part that attaches to the plastic frame) are broken. So if anyone has those and could see themselves living their lives without them, I would happily consider becoming their new caretaker. (I'll post photos when I have a camera at hand.)

Then there's the caps (I'll check with Dillen when I come to that) and checking voltages. And give the whole thing a thurough cleaning.

I still havent opened the RL60s, but I think I will try to fix the ABRs myself, following some of the posts on that subject that I've found on here. People seem generally happy with the results, so I'll give it a try.

I

Johan:

Thanks Eugene.
Dillen actually sent me a PM suggesting that it might be the male dins inside the machine that had bad solderings. I connected the speakers directly to the female dins inside, and sure enough, they both worked. So I figured I'd give it a shot. I desoldered the two dins and soldered them back in. I also used a little hot glue to fix the dins to the PCB, just to give them a bit more strength. After that, testing and putting it all back together the BC plays beutifully on both chanels.

Would you believe, it seems Martin was right! :-)

I'm really happy to have that one sorted out.

I still need to get the hinge fixed on the programming section lid. I took the whole thing out while I was in there, and it appears both parts of the hinge (the one that slides into the alu plate, and the part that attaches to the plastic frame) are broken. So if anyone has those and could see themselves living their lives without them, I would happily consider becoming their new caretaker. (I'll post photos when I have a camera at hand.)

Then there's the caps (I'll check with Dillen when I come to that) and checking voltages. And give the whole thing a thurough cleaning.

I still havent opened the RL60s, but I think I will try to fix the ABRs myself, following some of the posts on that subject that I've found on here. People seem generally happy with the results, so I'll give it a try.

believe it ..... it is no surprise to me at all dillen would offer another solution that "worked". He has helped me me and others countless times.

here is picture of mine after the rebuild. A truly magnificent machine....

Yeah, I know. I haven't posted much on here, but I've read a lot and it's really no surprise to me either. Hence the ":-)".

Your BC looks really nice! I can't wait to get mine cleaned up. But I'll tend to caps and other things first (well, I'll obviously clean the inside while I'm in there). I think it will look really good.
Mine is really in excellent condition, it just needs some tender melamine spunge love on the alu surfaces, and should look brand new. The veneer is also in great condition. And with the SC77 that I got with it, which looks like it came from the store yesterday, it will just look awesome.

I really appreciate your input, Eugene! Thanks!

/  Johan

Here are some photos of the broken hinge parts. If anyone has these, please let me know. 

Thanks!

/  Johan

You will find your parts at some point Johan. When I rebuilt mine I made a photo journal of the whole process. I could share that with you if you like. It is on another Non B&O site however.

I even reworked the remotes. and I have also rebuilt and recapped a few sets of Redline 60's. Also photo documented.

Thanks for your encouraging words, Eugene! Much appreciated.
I would love to see those photos, I'm sure it would be a good aid.
Thank you very much!
/  Johan

Johan:

Thanks for your encouraging words, Eugene! Much appreciated.
I would love to see those photos, I'm sure it would be a good aid.
Thank you very much!
/  Johan

this link should work

http://www.flickr.com/photos/outland1/

Awesome! It's always good to have pictures of things taken apart.. it's easier to figure out how they come out.

Thanks a bunch, Eugene!

/  Johan

but be careful not to catch the Beovirus its a nasty little bug.

Eugene:

but be careful not to catch the Beovirus its a nasty little bug.

Too late, I'm afraid. I think I've caught it bad.
Things acquired in the last two months (before that I didn't have a single B&O or related thing):
Beomaster 1900 which came with two S25s, 2 CX50's (I just refoamed those, and use them with
the 1900 in the kitchen). Then I got a Beomaster 7000, Beogram CD 7000, Beocord 7000 and
Beogram 4500 (I was real lucky on this one, I got the stuff for about the equivalent of < $300,
otherwise I would have not been able to afford such a system at the time), the Beocenter 7700
with MCP 7700 and the RL60s and the SC77, which also was a bargain. Then 3 * Beolink 1000.
And I almost forgot the Beocenter 9000. Finally I got two Innovus RAone dimmers.
I believe that's all. For now. :-)

I use the Beosystem 7000 as my livingroom system. The 1900, as mentioned is in the kitchen.
The rest isn't really used at this point, but we'll be moving to a bigger place shortly, so that's my
"reason" for getting all the other stuff. :-)
/  Johan 

oh dear.... I am afraid there is no known cure .... Marantz didnt work and neither has Tandberg. I always come back to the Beocrack. It is my fix of choice.

Mine started about 4 years ago with a lucky grab off eBay for a mid 80's system 3000 Beomaster Beogram and CDX. Still one of my favorite sets.

I think I have about 50 pieces now. I binged on BM2400's then BS 5000's The last were a handful of Beomater 1600's. It never stops.

Well, it hasn't developed into a problem.. yet. I still can kind of motivate the stuff I've got so far.
I can stop whenever I like, I promise. :-)
But seriously, it's crazy how it grabs you. Never thought that would happen when I first bought that BM1900.
Oh well.. as long as it's fun.. and I do find great pleasure in repairing stuff, so I guess there'll be a steady and
constant stream of stuff coming in from now on. 

Eugene:

oh dear.... I am afraid there is no known cure .... Marantz didnt work and neither has Tandberg. I always come back to the Beocrack. It is my fix of choice.

Mine started about 4 years ago with a lucky grab off eBay for a mid 80's system 3000 Beomaster Beogram and CDX. Still one of my favorite sets.

I think I have about 50 pieces now. I binged on BM2400's then BS 5000's The last were a handful of Beomater 1600's. It never stops.

If you ever need to unload one of those BM1600s, my daughters need their first receiver soon......