My latest purchase is a beocenter 7700. The device is comlpete and just about everything works. All the displays are fully functional and buttons and potentiometers aren't crackling while using them.

But this doesn't mean there's nothing to do... First of all, a thorough clean is needed. It seems like somebody has poured milk or something on to the top panels as there appears to be some very thin film of some sort of laqcuer all over the surfaces. All the panels need adjusting too. All the panel gaps are uneven and nothing really fits. And i guess i'm going to have to polish the plexiglass surfaces too.

Some real problems were found too:

-I can hear some high-pitched buzz on the background of every sound source. It gets louder if i turn the volume louder.

-The cassette player obviously needs new belts. The motor appears to be ok.

-The record player has some issues. The needle doesn't follow the track but starts to slide towards the edge of the record. Is this due to worn stylus or is this some sort of an anti-sskate issue?

After i've done these small fixes, this Beocenter seems to be in very good condition. Oh, and one strange thing is that this is a "white edition" 7700. I've understood that all of these Beocenters came with wooden panels. The white panels are well made and they don't look like someone has done them afterwards.

Another one I skipped and you bought

If you take a close look at the needle, I'm sure you'll find that the actual tip is missing completely or badly chipped. If you still get some noise from both channels, that cartridge is a good candidate for sending to Axel in Germany for retipping.

Don't use anything too aggressive on the panels, I believe they are not bare metal but have some kind of a coating from the factory. If it peels off somewhere, they'll never look even again.

The cabinet trim panels could easily be original white.
All the Beocenters of this series were available in white, just a bit rare to see.
Nice project !

Martin

tournedos:

Another one I skipped and you bought

If you take a close look at the needle, I'm sure you'll find that the actual tip is missing completely or badly chipped. If you still get some noise from both channels, that cartridge is a good candidate for sending to Axel in Germany for retipping.

Don't use anything too aggressive on the panels, I believe they are not bare metal but have some kind of a coating from the factory. If it peels off somewhere, they'll never look even again.

I could even get some clear sound from both channels if i slightly pushed the cartridge down with my finger. But the tip looks quite flat 'though, so i guess retipping is needed. Is this the place i should send my gartidge fo retipping? http://www.schallplattennadeln.de/

The coating from the plexiglass display was already peeling so i wiped it off. Looks better now. The aluminium panels might need some solvent as there's something really sticky stuff on them, which doesn't just wipe out. The aluminium looks "natural" to me -meaning i cant see any protective coating on them.

Do you guys have any suggestions what could cause the buzzing sound? Some grounding issue? Bad caps again?

-Pirkka-

VW411:

I could even get some clear sound from both channels if i slightly pushed the cartridge down with my finger. But the tip looks quite flat 'though, so i guess retipping is needed. Is this the place i should send my gartidge fo retipping? http://www.schallplattennadeln.de/

Exactly. Axel will also change the suspension for the needle, and you'll essentially get an as new cartridge - much safer bet than buying a second hand piece, which will probably fail soon as well.

I'm sorry I don't have any good theories on the buzz. It could well be some missing ground connection or shielding which attracts crosstalk from some digital bus. 50/100 Hz would be an almost certain case for bad PSU caps, but I'd expect high-pitch buzz to be something else.

The Beocenter 7700 has a general grounding problem that could be the cause of the hum/buzz.
If the Beocenter stops buzzing when you open the right side section up to service position, the diagnose
is complete and the cure here:
The cassette section is held by three screws, two at the rear corners and one towards the front.
Cover the frontmost screw (yellow circle in the photo) and the bracket it holds with a piece of thick tape or two.

Martin

Cool! It really was that simple! After adding the tape the buzz is gone!

I tried the cassette player also, with some belt i already had. I can hear the motor, but nothing happens. Well, I'll leave the cassette player as is till i get some correct belt.

And i also found that the hinge for the programming section's lid is cracked in several places. I'm going to weld those cracks and see if it works. If not, i'm going to have to find a replacement somewhere.

VW411:

Cool! It really was that simple! After adding the tape the buzz is gone!

Gotta' love Dillen!

Indeed

Since you noted that you got some good music out of the record player while pushing on the arm... I just realized, do these have the same mechanism as the earlier automatic types, where the lowering pin for the tonearm gets stuck? If that is the case, you might still have a usable cartridge, but the tonearm just doesn't drop low enough!

Well done !
I can supply new belts if you need.

Martin

tournedos:

Since you noted that you got some good music out of the record player while pushing on the arm... I just realized, do these have the same mechanism as the earlier automatic types, where the lowering pin for the tonearm gets stuck? If that is the case, you might still have a usable cartridge, but the tonearm just doesn't drop low enough!

This has similar mechanism as for example beogram 1700 has. There's no similar pin like the earlier models like 1202 had. I'm pretty sure it's just a case of a bad stylus.

I got the lid hinge working better, but there's a small "nose" that just couldn't bear the leverage and cracked again.

So if anyone knows which part i'm talking about and has one for sale, i'd happy to buy it!

I think, i'm going to replace the white panels with teak veneer at some point as i really like that vintage look. And the white panels have some scratches anyway. I tried to adjust the aluminium panels too and got them fitting better but i'm still not quite happy about the way they are looking. It seems like the lid's been warped but i doubt that. I'm sure it just needs careful adjusting to look perfect.

Martin, i'll contact you when i know what else i'm going to need. I have three VX5000's waiting for maintenace + a pair of BeoVox 5700's. And i bought a Beocenter 3500 to a friend and that might need some work too...

-Pirkka-