Hello,

I've just got a nice Beocord 8000. I want it back to life!

I removed the horrible belt rests (more akin to tar, really, yuck) that had spread everywhere and I now need new belts.

I also changed the motor which was very noisy (I had the same Alps unit in stock!). The funny thing is it's actually smaller than the one on my Beocord 6000!

The remaining problem is that the motor spins as soon as I plug the deck.

Is that a normal behaviour, when the belts are out?

Otherwise the capstan wheel and the heads amazingly all look like new, the deck shows very little use.

Any thoughts?

Thanks in advance,

Jacques

Martin can supply belts for these Beocords. I have an 8004 that he fixed up for me and it's great.

The motor should start spinning as soon as it is out of standby, but should stop when the unit is switched to standby.

j0hnbarker:

The motor should start spinning as soon as it is out of standby, but should stop when the unit is switched to standby.

Thanks for the answer John.

Yes I know (I have a Beocord 6000), but on this one the motor never stops!

I was wondering whether this is down to the absence of belts or an electronic fault.

Anyone please? I'm becoming crazy![:'(]

I don't know anything about the BC8000 so this could be a longshot but anyway. There could some sensor in the tape mechanics that switches the motor on and off. Now if the mechanism was stopped (when the belt was jammed or cut or something in the first place) the mech. might still be in playback (you would have noticed this as the heads would be engaged) or winding mode, motor switch on and the motor keeps running. You could try turning the rest of the mech by hand for some revolutions to see if it does something. The fact that there is voltage to the motor in standby mode sounds strange, though. 

I would say Martin is your man for both belts and for better information on the topic!

Thanks.

Yes this is strange. I can't figure out what stops the motor (its power supply) when it's put in standby. It's not very clear on the diagram (and I can read a diagram) and all voltages are nominal. Now there is indeed some optic device inside the mech but I don't know how this works. I tried my other mech's belts but it didn't make any difference.

MARTIN PLEASE!!!

Jacques,

I just fired up my BC6000 (the source of your repaired part) to try and offer some insight. Unfortunately, it is dead to the world...

I am sure Martin will be along.

Regards,

Ah well, thank you all the same Jeff!

I've studied the auto-stop circuit and it works. Alas this doesn't affect the motor in any way.

The constantly running motor fault, I've had two times recently, both on Beocord 8004's though but the
circuits are quite identical. One was Jeff's if I remember correctly.
It's a blown driver transistor on the controller board. I don't remember exactly, I think its TR9 (?), a BC547
or something like that. I have no idea why this happens but if it also did so in your machine, it will be
put down as a standard issue (and the reason the motor has died, no doubt).

Yes, I have new belts and motors and you have an answer to your PM regarding this.

Martin

EDIT: Just realized that Tim have had the same fault on a 8004, so that makes it three - plus maybe yours.
He also confirmed 4TR9 as the culprit.

Okay, thanks!

I will try to change it tomorrow.

No PM though! But yes I'm interested in the belt and motor.

Couldn't wait!

I replaced it (4TR9, BC547B) with a 2N3904 and it's a victory! Definitely a standard issue then.

Martin, thanks for sharing your invaluable knowledge. So, you have belts and motors?

On my deck, it's a smaller variation, the silver Matsushita one without the external transistor, curiously dated 1985 with reverse polarities (not sure about the quality when compared to the gold bigger one on my 6000). There is a B&O service sticker on the back dated 1986.

Well done !

The motors I have are much smaller than what was originally mounted.
They are of the last brand and type supplied as replacements from B&O.
I've found none of the large original ones with the golden housings to be
particularly good. Or maybe it's just because the majority
of those, I've seen, were bad.

Sorry about the PM confusion, it was someone else, referring to this thread.

Martin

You did the job! I was your eyes and hands!

Is your replacement motor the same as this one?

Mine is dated 1985 (but I've got another one, in better shape, dated 1981—it was on a NAD deck).

No, it's a bit smaller.
Last supplied by B&O about 6 years ago, I think.

Martin

OK. I tried the aux input, but nothing.

Then I realised P13 connector was loose. In fact there were several broken pins. So I changed the connector. I made no mistake, I'm sure.

Anyway, black smoke appeared from underneath the alu panel. Result: IC2 LF 347 burnt.  Before it wasn't powered at all, so it was impossible to predict!

And of course, I don't have any in stock. I just soldered a 14 pin support. 

Should I worry?

Right then. I'm making some progress on this Beocord.

I found three shorted caps (ROE types, C102/202; C1) and I now get sound out. The quality is good. Also, RL1 had to be cleaned.

But I still can't figure out why IC2 (LF 347N, peak meter rectifier) destroyed itself. It gets +/- voltage, the diodes and the resistors are good, there are no shorts anywhere. As soon as I can get hold of two others (guess why) I will experiment further (I'll wear safety goggles, don't worry!). I've soldered an IC holder for that purpose. Measuring voltages on pins shows there's nothing wrong.

Another Beocord saved!

I received Martin's belts and motor today, a new LF347 and we're back in business!

I'll never know why the IC burnt in the fist place.

I also had to change all PSU-related red ROE caps, all shorted... of course!

Thanks to all.

Edit: the deck plays correctly, but there's too much treble in recordings regardless of tape type, adjusting bias has no effect it seems.

Also, there is a small whining noise (half a second) when I press "rec open" after recording. Hiss is in good order.

Any clues?

Edit2: never mind, the CrO2 trimmer has effect on type I too. Silly me!

The Beocord 8000 is still working fine.

I still have this very short squeal when I turn REC OPEN off on one channel, but recording is okay.

Speed stability isn't first class however , in spite of total re-lubrication (I did that on my superb BC 6000 to great effect), rubber parts cleaning, and new belts. I did notice the new capstan belt is very tight. The capstan wheel looks like new. Everything is free on their axles. Motor voltage is constant. No springs or anything else are missing—actually there is one more spring on the left side I haven't got on the '6000!

Any thoughts?

You need to replace ALL electrolytics in this deck. I also had similar problems.

As for speed regulation....

1) Make sure belt is riding on the center of the pully. Some belts have a tendency to slip to the edge where the diameter is larger.

2) During reassembly make sure the felt damper is fitted properly. It is mounted on a copper pivot arm and is spring loaded. Very often it gets bent during assembly/disassembly and rubs against the  spindle.

Thank you Auric.

1) No problem, the belt is new, supplied by Dillen,

2) I fixed that long ago, that was the most obvious problem (rattling noise) which is the consequence of sliding bearings in the cracked plastic housing.

The caps are now all replaced, except for the PSU ones (the two 1000μF and the big 4700μF) which are still good (checked filtering).

Okay, I renewed the PSU caps (when doubt seizes you...), but it makes no difference!

Umm

Double double triple check polarity on the electrolytic caps. Verify with schematics! A few times (don't recall if it was on this unit) I have found incorrect silk screening on the PCB for the polarity.

Have you tried different cassettes?

What is condition of pinch roller?

Are heads and tape path clean?

Is capstan bearing lubricated?

Check metal plate that holds capstan in place. Is it centered properly over the shaft and properly lubricate?

Just some more ideas....

Hi,

I still have the wow problem, audible only on piano sustained notes. Everything seems okay, clean and free to turn, the pinch roller looks like new, heads are clean (like new also), the capstan plate is in place and lubricated. I don't have a clue, really.

Maybe you do?

Thanks,

Jacques.

Sorry, I've checked my dictionary, it's not wow, but flutter, "it can be heard as some sort of strange fast vibration (trembling) of the sound, much faster than a normal vibrato" (Erwin Timmerman), so it's supposed to be the capstan, but a swap with a known good one doesn't change the problem.

Any thoughts then?

The left reel brake ?
There's a little short and flat, spring operated metal arm that brakes on the perimeter edge of the
reel table. It's very easily bent or even working on the wrong side of the perimeter edge.

Martin