[Dillen]

Replace the wedge-shaped belt for the carriage motor.

Also dirt and/or dry lubricants towards the leftmost end of the threaded spindle can cause
excess friction and make the belt slip.
Clean the threaded shaft and add a handful tiny drops of teflon oil.

Martin

[Dillen]

You cannot tell if they are any good by looking at them.
They will be out of spec by now, that’s almost guaranteed after all these years.
Capacitor kit here.

Martin

[Dillen]

Running the power output of Beomaster 8000 to the input of another amplifier (Beolab 8000 is an active speaker) could easily destroy both.
How did you connect it?

Martin

[Dillen]

It’s a mains phase issue. The metal chassis’ of your products are capacitively coupled to neutral, so if not phased correctly (coupled to live) a very small amount of AC current
will run through your body and to the ground you stand on.

Try rotating power plugs 180deg. Start with the Beomaster as it is the one with most connections to other products.

Martin

[Dillen]

A scope to the signal path would reveal the cause in a few minutes.
Lacking a scope you could compare DC voltages on the transistors in the preamp L+R sections.

Martin

[Dillen]

The problem is that the carriage is moving while the tonearm is lowering.
The diaphragm adjustment method can be found in the service manual.

And something in the damper linkage still doesn’t move exactly as it should, causing the tonearm
to drop fast if lowered soon after being raised.

Martin

[Dillen]

Nice video.
Wrongly adjusted tracking opto (diaphragm).
Could also be that the tonearm alignment is way off, but that’ll usually be visible, and yours doesn’t look that wrong.

Martin

[Dillen]

Was this problem also present before you started work on the Beomaster?

Martin

[Dillen]

The decoder is the module to the right of the amplifier module in this photo.
It has no visible leads out side this.

When Tape or Phono is selected as source, the stereo light should be lit.
If it flashes, it could be because of a bad switch contact or the lamp is not securely fixed in
its socket. Or the lamp itself is on its way out.

Martin
(Photo from http://www.vintage-radio.net)

[Dillen]

The stereo decoder module was an optional extra in Beomaster 900K.
Not all Beomasters had them installed.
If no stereo decoder module has been installed, FM reception will be mono only, and the stereo indicator won’t light up.

Martin

[Dillen]

And some versions have protective diodes at the datalink signals. They can short.

Martin

[Dillen]

This?

Beogram 1200 1202 3000 Platter Spindle Gear 2700005

Knock out the small steel pin that goes through the gear, then the hub with spindle etc. can be lifted up.

Martin

[Dillen]

New datalink pins here:
Beoparts-shop

Martin

[Dillen]

No!
A good rule of thumb is to start with a trimmer in its center position, as that
usually won’t be far from its correct setting (if everything else in the circuit is fine).

Besides, the amplifier PCB in Beomaster 3000 (-2) has left and right channels mirrored,
so fully clockwise would mean max idle for one channel. Not good!

Martin

[Dillen]

The original gaskets can become immensely brittle.
In these cases it’s nice to have the possibility to simply replace them.

Martin

[Dillen]

Oh, I agree that looks horrible. It would be difficult to restore back.

Beocenter 4600 and Beocenter 7002 use different tonearms. The one in your photo could be
from a Beocenter 4600.
Which one do you need, – I could look in the dungeons for the right part.

Martin

[Dillen]

That’s not antiskating. It’s the tracking force setting.
It’s something you would normally not take apart. Originally, it was sold only as a complete assembly and, unless you are a really skilled DIY’er, I would recommend you replace it as such.

Martin

[Dillen]

And use ESD-protection!
These things are highly sensitive to static electricity.
Many owners experience that new lasers don’t work, – and while it is correct that
many asian “counterfeits” won’t work, or only work for a few hours, many lasers
are damaged by static electricity, – either during shipping, if shipped without
shorting clamp and/or ESD-shielding or by handling without taking
proper ESD-precautions.
I have seen many of both cases.

Martin

[Dillen]

There can be many reasons.
A photo or two would help us diagnose the issue.

Martin

[Dillen]

The belt will not be the problem then.
I suggest you add a small drop of oil to the motor bearing. Usually, the outer (visible) bearing will dry out before the inner, and it’s also the outer bearing that takes most
of the sideways load, so I would start there.
A little sinter/spindle oil would be the choice.

Martin

[Author]

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