[Dillen]

Check the fuses for the amplifier section. (F3/F4 I think).
Sounds strange, I know – but try it.

Martin

[Dillen]

Measuring with an ohm-meter (“DC-resistance”) will not give the impedance (“AC-resistance”).
It may come close, but don’t count on it.

Martin

[Dillen]

An IF stage slightly off correct alignment can cause this.
As pronounced as this, it could be the last stage before the detector.
Don’t attempt to do any alignment unless you have the proper instruments for it.
There are ways to do it without, but it usually requires more than average experience.

I don’t think it does, but if your Beomaster uses AF116/AF117 transistors in the IF stages, one or more of them could also be bad (or just weak). AF125/AF126 are not as fault-prone.

Martin

[Dillen]

What, in your opinion, would be a better RIAA curve?

Martin

[Dillen]

The damping grease is a bit too thick for this.
The action will be smooth, but the timing may not allow for complete opening and closing.

I use this stuff for the large gear and the four rollers (practically every place where plastic works against metal):

https://www.dksoundparts.com/product/grease-for-carriage-metal-rails-etc/

Martin

[Dillen]

Right kit:
https://www.dksoundparts.com/product/electronic-service-kit-beogram-cd5500-cd6500-cd7000/

Any good repairshop should be able to do it.

Martin

[Dillen]

If the drive refuses to read the disc, the first thing to replace is C2103 (and the rest of the electrolytic capacitors on the servo board).
C2103 MUST be a blue axial Philips or BC. I know it sounds strange, but it is a fact that not just any capacitor from any brand will work in this position.
The capacitance is not that important, it could just as well be a 47uF, but fitting anything but a blue Philips/BC cannot be guaranteed to work.
It has certain filtering properties not found from other brands.
A convenient kit is available from Danish Sound Parts containing the right capacitor.

Martin

[Dillen]

Danish Sound Parts

Martin

[Dillen]

C2103 must be a blue axial Philips/BC. That’s the only type I have found to be guaranteed to work.
I suppose you would have known it, if you fitted this type, so I suggest you replace it again, this time with such one.

Martin

[Dillen]

What did you fit as C2103 (brand/type)?

Martin

[Dillen]

A transformer will always hum a bit. It’s in their nature.
New correct rubber feet are available – visit our sponsor Danish Sound Parts.

Martin

[Dillen]

The transformer is at the back left.
But it is most likely what you hear.
Does the hum go away when you lift the Beogram?
Has the deck lost its rubber feet?

Martin

[Dillen]

What are the symptoms?

Martin

[Dillen]

The one with the lifted pin in the last photo is a 47uF 25V.
How do you test them, and with what?

Martin

[Dillen]

I wouldn’t worry as long as we are within +/-10%.
I don’t think the power plants can guarantee a tighter tolerance anyways.

Martin

[Dillen]

1,
The kit description does not mentioned thermal paste, so it is not included.
The thermal paste rarely needs attention in these models, but if you must replace it I suggest you
get some of the good old white stuff. The newer grey stuff dries out very fast and is useless.
This guy made a great video:
https://www.youtube.com/watch?v=psY_RV1NjHM

2,
A bulge points to internal overpressure. Replace them!

3,
Electrolytic capacitors from 1987 are no longer up to spec. That’s fairly safe to assume.
The boards can bind immensely. Pull and wiggle and it will come out.
Look at the back of the boards and compare the numbers there to those mentioned in the kits descriptions at Danish Sound Parts.
https://www.dksoundparts.com/product/crossover-capacitor-kit-beovox-beolab-penta-early-version/
https://www.dksoundparts.com/product/crossover-capacitor-kit-beovox-beolab-penta/

5,
A rubbing woofer must be replaced. Look at f.e. Ebay for a good original one.

6,
It’s glue. It holds the thin wires running from the flex wires to the voice coil.

Don’t get me wrong, but are you sure you have enough experience to do this?

Martin

[Dillen]

R40 is the NTC resistor for the over-temp protection circuit in the amplifier section.
It has nothing to do with the wiring of the mains transformer.

The mains transformers shown on page 8-4 for 100V and 120V are different from the one used for 110/130/220/240V.

Seeing as you have a Beomaster currently set for 220V:
If you have 110V in your mains, I would convert to that.
If you have 120V mains I would convert to 130V.
If you absolutely must convert to 120V you must replace the transformer with a correct one (8013299, that has a thermal fuse built-in).

You must also replace the mains fuse with one of twice the amp rating. (Half voltage – twice current – same power, also known as Ohms law).

Martin

[Dillen]

If you order bearings from Danish Sound Parts, you will not need to add any oil.
They come pre-oiled, ready to mount. That also goes for the reservoir felts.
Just clean the motor spindle thoroughly, as any remains of old lubricants will be in the way,
and make sure the spindle is centered in the motor so it runs freely without rubbing on anything.

You can read more here:
https://www.dksoundparts.com/product/motor-bearings-set-for-beogram-motor-with-3mm-spindle/

Martin

[Dillen]

69er, can you show us a photo of the board (front and backside)?

Martin

[Dillen]

I have never seen a tray belt cause a read failure.
If the belt fails, the tray will usually not open fully – or not open/close at all.
If the tray doesn’t close fully, the disc will not start to spin.

The symptoms of the disc spinning for a few seconds, not reading and then stopping is a sign of a laser starved of power.
Replacing the capacitors on the servo board will alone fix this in 95% of cases.
The last 5% is usually dirt on the laser lens or a combination of the two.

If the disc doesn’t start spinning at all, there could be a problem with cracked solder joints (as shown above) or
a badly seated ribbon cable for the disc drive.
The laser itself rarely dies. I don’t recall ever replacing a laser in one of these decks, and I’ve done many.

Martin

[Author]

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