BeoGram

Re: MMC 1/2/3/4/5 Pinout?

ablaumeise — Fri, 02 Jan 2009 17:09:52 GMT

I'm finished!

Well, at least as far as possible.

I have repaired all three tonearms and was able to build two nice working & looking units with these. Sadly the third unit (which is made from the worst looking parts) is missing a part.

The mounting for the tonearm is broken, but I thought this could be fixed as the broken off part was included. Now it turned out that this broken off part is from another unit and doesn't quite fit on mine.

Anyway, thanks to all for your support and encouragement.

Fixing that wiring isn't even that difficult after you've done it three times. So if someone has a unit that needs to be repaired...

By the way, I have one working tonearm left over now. Anyone interested?

Re: MMC 1/2/3/4/5 Pinout?

ablaumeise — Fri, 19 Dec 2008 16:24:00 GMT

Today I finally got to work on the second unit.

This one was even worse, seems like they used another type of glue on that unit (that sort of cable channel and the soldering points were originally covered with glue that had to be scratched out) . I needed hours to remove it and that was just for the plastic part...the part of the cable channel that is in the metal part is still blocked by glue.

At least I was able to solder on the new cables, which means the hardest part is already done.

I hope this unit will be finished tomorrow.

Hopefully I will get to work on the third one soon - I am really curious what that jacket might look like.

Re: MMC 1/2/3/4/5 Pinout?

Medogsfat — Sun, 14 Dec 2008 09:00:39 GMT

Let me know when you've finished them and I'll send you the jacket I wore for a while after I did these repairs - a bit hard to take off though as it buckles up at the back - it came with a padded room

Chris.

Re: MMC 1/2/3/4/5 Pinout?

Dillen — Sun, 14 Dec 2008 03:40:32 GMT

Well done indeed !

Martin

Re: MMC 1/2/3/4/5 Pinout?

Jandyt — Sat, 13 Dec 2008 19:42:53 GMT

Wow!
You must have heaps of patience. Especially if you are going to do it all over again.....twice!
Hats off to you!

Andy T.

Re: MMC 1/2/3/4/5 Pinout?

ablaumeise — Sat, 13 Dec 2008 18:43:07 GMT

I think I would be a bad neurosurgeon with needing about two attempts for each cable and breaking off parts.

Actually I planned to build one working unit out of three broken ones (as on one unit the tonearm was only broken once), but now that I found a way to fix that fault I will repair them all.

By the way, stripping off the shellac is not quite necassary. You just have to take care that the cut surface is either soldered exactly on the point or that it is covered with tin. Makes things a lot more easier, though you have to solder more exactly then.

Re: MMC 1/2/3/4/5 Pinout?

Medogsfat — Sat, 13 Dec 2008 12:02:14 GMT

You're not far wrong saying it is microsurgery. The ones I have fixed had the fine wires snapped which needed resoldering, I replaced them with bindings out of a solenoid from a defunct Beocord 2200. The hardest part is stripping the shellac off of the wire ends to enable one to tin them before sodering into place. Not an operation I could do now as my eyesight has been going downhill since I hit 42 - probably caused by doing this

I too salute you

Chris.

Re: MMC 1/2/3/4/5 Pinout?

Phil Hunt — Sat, 13 Dec 2008 11:52:00 GMT

I want to praise you for being able to fix that wiring. Are you a neurosurgeon specializing in micro-surgery by day?

Re: MMC 1/2/3/4/5 Pinout?

ablaumeise — Fri, 12 Dec 2008 17:34:43 GMT

Just wanted to say that it actually worked (at least I have finished unit 1 of 3).

As Chris said it is a thing one will never do again. In my case the tonearm was even broken at two points, so I had to disassemble the complete tonearm and reroute the cables. The worst thing was scratching out the glue in the mounting for the pickup....and then I even broke off one of the solder points. But after all it really works (with a lot of of glue, patience and new cables)!

Still two units to go....

Re: MMC 1/2/3/4/5 Pinout?

Peter — Tue, 02 Dec 2008 15:15:33 GMT

ablaumeise:
Thanks!
That is actually the thing I was searching for.
I already had a look at the service manual, but somehow I did not see that one.
Could it be that the service manual is missing a page? That circuit is only shown in the extra part of the manual referring to the Beogram 2000 & 5000. In the 1800 circuit diagram that board is completely missing.

Not one of mine in this case! I think the manual is just not very good! No idea why it shows in the 5000 and not the 1800!!

Re: MMC 1/2/3/4/5 Pinout?

Medogsfat — Tue, 02 Dec 2008 14:30:00 GMT

I've been there and done this repair myself a couple of times (I have the T shirt to prove it). Well done getting this far, it really is a painful operation and one I will NEVER do again.

Good luck and hope the results work out fine.

Chris.

Re: MMC 1/2/3/4/5 Pinout?

ablaumeise — Tue, 02 Dec 2008 11:01:59 GMT

Thanks!

That is actually the thing I was searching for.

I already had a look at the service manual, but somehow I did not see that one.

Could it be that the service manual is missing a page? That circuit is only shown in the extra part of the manual referring to the Beogram 2000 & 5000. In the 1800 circuit diagram that board is completely missing.

Re: MMC 1/2/3/4/5 Pinout?

Peter — Tue, 02 Dec 2008 10:38:19 GMT

I think this is what you need! It is in the 1800 service manual which you can find in the manual section.

MMC 1/2/3/4/5 Pinout?

ablaumeise — Tue, 02 Dec 2008 10:00:49 GMT

Received three broken Beogram 1800 from eBay today. Everything is working more or less fine, the only (and somehow strange) problem is that someone ripped out the Tonearms (on all three units!).

Now the cables running from the Pickup to the circuits are cut....I tried to resolder them, and luckily it works.

Now the only problem is that I have no idea which cable belongs where....the circuit reads L, R, LG, RG and ground.

I suppose ground is the tonearm itself and each of the others (left and right channel) belongs to one of the pickup pins (upper, left, right and lower pin).

Could anybody please tell me which one belongs to which pin?