Beogram 4000 Type 5215 - dial lights issue [solved]

20 replies
V(
Offline
Velvet (archived2)
Bronze
Posted December 3, 2018 at 08:16 GMT
#2209351

Hello,

 first post here in this wonderful forum. I started recapping and fine-tuning my BG4000. This beauty came from UK (I live in Italy) around 2005 in terrible conditions because of a bad packaging. Luckily nothing was broken but many parts were disassembled including the arm mechanism. I was able to put everything in place and let it work for many years since then.

But at a certain point it began to develop strange issues: self power-on, 7" not recognized and other little gremlins. Ok, time for a total recap and a tuning following service manual.

Recapping was done with Vishay, Panasonic and Nichicon electrolytics. One of the main unipolar caps was shorted and others were out of specs. Tantalum were OK but I replaced with electrolitycs. Now the motor spins fine and quiet, sine-wave is clean both at 33 and 45 rpm at 6,2Volts (@33), no more self-power on.

 

But I have a new issue: the two dial scale lights self-power on when I plug the beogram to mains. They're always on, even if I press OFF . Other functions are correct (strobe light, motor, arm transport power On and OFF). 

Any suggestions or ideas will be much appreciated..

 

HC
Online
hcraig244
Silver
Posted December 3, 2018 at 09:46 GMT
#2209352

Hi

I am currently going through this exercise and I'm pretty sure I have the same problem....I have discovered that the reed relay 2MS2 24vdc contact is permanently on the closed condition, therefore illuminating the scale lamps on power up, they should only illuminate when the relay coil is energised. It looks like the only solution is to replace the reed relay, this will be very tricky as the relay coils are very delicate...the connecting wires are hair thin and graet care will be needed...you, and I, will also need to source a replacement reed switch of the correct size, wattage and Normally Open (I think) shelf condition......good luck, and post pics ;¬)

DI
Offline
Dillen
BronzeModeratorFounder
Posted December 3, 2018 at 10:06 GMT
#2209353

Quite common to see the contacts welded (or magnetized) together.

Leave the coil in circuit and pull out the reed element (glass tube with contacts).
It can be replaced separately. Just find a suitable size.

Martin

V(
Offline
Velvet (archived2)
Bronze
Posted December 3, 2018 at 10:27 GMT
#2209354

OMG that sounds a difficult challenge... I will take some measures around the relay this evening. I guess there are no direct interchangeable parts on the market today :-(

 

HC
Online
hcraig244
Silver
Posted December 3, 2018 at 10:53 GMT
#2209355

Martin

Thanks for the tip.....I was going to remove the whole thing but will take a closer look now, can you take a look at this, I'm not sure what is meant by 15=20AT is it the magnetic field required to actuate the switch?

HC
Online
hcraig244
Silver
Posted December 3, 2018 at 12:48 GMT
#2209356

Got it......

AT means Ampere-Turns and is a standard unit categorizing the magnetic sensitivity of Reed Switches. The AT value is measured by centering the Reed Switch in a standard coil, to which an increasing current is applied. At a certain current (Amps) the Reed Switch closes by means of the magnetic field generated by the coil. This is the Operate (or Pull In) value, calculated as Amps x number of coil turns = AT. Reducing the current passing through the coil until the switch reopens, the Release (or Drop Out) value can be obtained.

V(
Offline
Velvet (archived2)
Bronze
Posted December 3, 2018 at 13:03 GMT
#2209357

Great! But i guess the original switches AT is unknown...or not?

 

 

V(
Offline
Velvet (archived2)
Bronze
Posted December 3, 2018 at 13:03 GMT
#2209358

Great! But i guess the original switches AT is unknown...or not?

 

 

DI
Offline
Dillen
BronzeModeratorFounder
Posted December 3, 2018 at 15:30 GMT
#2209359

Find some in the correct physical diameter to fit inside the coil.
Don't worry too much about the magnetic parameters. The old switches weren't that sensitive and the coils therefore quite powerful.
If a reed relay won't switch correctly, try rotating it a bit.

Martin

V(
Offline
Velvet (archived2)
Bronze
Posted December 3, 2018 at 20:56 GMT
#2209360

Thanks Dillen.

I took some measures around the relays, both in stand-by and On. Please see pic. 

 

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