[Dillen]

Shorted solenoid driver transistor?

Martin

[Dillen]

Could be a bad relay.
There are two, found on the large tape controller board under the turntable.

Martin

[Dillen]

radzio222 wrote:

But it doesn’t start event if I’m on CD mode.

Still normal.
Press CD instead, – and it will also close the door if open.
Same as with all other B&O CD players.
Martin

[Dillen]

Beocord 2000 prototype in palisander veneer.

Plus other minor differences:

Martin

[Dillen]

Burned output stage.
Not a job for an untrained – with all due respect. Repairs like this can give even highly
skilled tech guys a good run for their money.

Put short – replace everything from the differential amplifier outwards.
Then power up slowly using a variac while keeping an eye on the idle current and DC offset. Follow up with adjusting the idle.

Martin

[Dillen]

radzio222 wrote:

I found also that when i put CD and close a door it is not starting reading the disc, I need to push CD button

That’s normal. Closing the CD door should not be reason to f.e. switch from radio, or what else is playing, to CD.
Pressing CD, on the other hand, should.
Martin

[Dillen]

Thanks for the photo.
They are bipolar.
Some also have the word “Bipolar” printed across the cap at the “positive” end. Perhaps
visible if you rotate them a little.
Used heavily in B&O passive speakers.
The polarity marks merely indicates which pin is connected to the caps metal house.
But replace them – they will be out of spec by now.

Martin

[Dillen]

Should the unit operate without the aluminum covers in place?
Yes.

Does the wood trim need to be pushed in to operate?
No.

Can the fuses be tested or replaced?
Both. But some tech skills are required, and a fuse rarely blows for no reason.

What type of fuses are needed?
Depends on the exact version of Beogram 4004 – there are several.

Martin

[Dillen]

They should definitely be bipolar!
Are you sure you are not just seeing marks indicating which pin is connected to the caps alu housing (for shielding purposes in some applications)?
That can sometimes confuse.
Photo?

– But they would need replacing anyways due to age.

Martin

[Dillen]

That’s the type used for serial number 1524001 or greater.
I have had many Beomaster 4400 on the bench and only had very few bad potentiometers – but it can and does happen.

Martin

[Dillen]

Strange symptom, but could well be a bad volume potentiometer.
Note, there are two different types (of all the potentiometers), they have different
mountings, and they are not interchangeable.

Martin

[Dillen]

Sure it’s not just swapped sliders?
Volume should be the leftmost slider.

Does the balance control work as intended?
Bass and treble potentiometers are identical (if memory serves), Balance has reverse tracks, and the volume control has tabs for loudness.
So no, you cannot use anything but a volume potentiometer for volume.

Martin

[Dillen]

If the motor leads were desoldered, they could also be reversed.

Martin

[Dillen]

Center puck seized in the down position?
Using a record weight? – Don’t!
Using an antistatic mat? – Dont!
If the latter throw the mat away or sell it to somebody who cares less about correct tracking angle and risk of stylus damage. It has no use on any Beogram anyways.

Martin

[Dillen]

yachadm wrote

By adjusting the platter height at the center axle, he screwed up the 23mm tonearm height.

– And the tracking angle.
All in all a clear example of someone who doesn’t know what he is working with.

Martin

[Dillen]

Stylus tip looks round.
If indeed so, that would be the reason.

Martin

[Dillen]

Can you tell if the laser tries to seek focus? – Does it move up and down a few mms when you press play without a disc loaded?
Is the laser emitting light? – The face-facing camera on f.e. an iPhone can usually see the light.

Martin

[Dillen]

A lead broken off inside the Beograms plug?
Problem with the Beomasters input/preamp? – Perhaps a broken trimmer?
Defective MMC cartridge?

Martin

[Dillen]

C2103 on the servo board is critical.
Fitting a low-ESR cap here is the recipe for trouble. It must be a blue Philips/BC axial type.
A kit exists for this particular problem.

Martin

[Dillen]

The mech. things (power switch slider etc.) in the switch group could need cleaning and the contacts perhaps a shot of contact cleaner.

Martin

[Author]

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