BeoGram4002 Typ 5503 repair

11 replies
AL
Offline
alf
Bronze
Posted June 28, 2015 at 08:41 GMT
#2222289

greetings all,

I am in the middle of trying to revive one of my old 4002 tables.

apart from the broken shutter/servo globe that I am still chasing,

the table won't spin when  '33'  is activated ?

it starts and spins perfectly when  'On'  is activated - speed change switching between '33' and '45' does also work fine!

FYI: at the moment there is no shutter globe fitted, which should have no bearings I presume ?!

as with this model, almost every connection between moduls is hard-wired, no plugs :-((

looking at the lay-out of the keyboard and what is actually happening when '33' is depressed, I would follow the violet wire to the main board ending near ( 1C1, 1D2, 1TR1) and or 1TR8.

are one of these components likely to cause that problem or am I far off the track ??

any assistance is greatly appreciated - as always :-))

cheers, ALF

 

AL
Offline
alf
Bronze
Posted July 4, 2015 at 15:42 GMT
#2222290

ANYONE ??????

Going to replace most of the metal-tin transistors as a first step !

ALF

DI
Offline
Dillen
BronzeModeratorFounder
Posted July 5, 2015 at 06:04 GMT
#2222291

Is that the record cleaning function, that doesn't work ?

Martin

AL
Offline
alf
Bronze
Posted July 5, 2015 at 06:56 GMT
#2222292

yes Martin,

Precisely the problem - some of the 'tin-transistors' seem suspicious when checked ?!?!

ALF

AL
Offline
alf
Bronze
Posted July 7, 2015 at 12:29 GMT
#2222293

Some other problems have emerged:

There seems a discrepancy between the circuit diagram and actual fitted components:

Fitted 4R4 = 8.2 ohm, circuit diagram 4R4 = 82 ohm ??

When 'ON'  is activated the arm moves accross but as soon as it lowers the carriage

Races halfway towards the spindel, the arm lifts and the carriage moves back to its resting position ?

I tried to adjust the diaphragm without any success.

All this happened after replacing all old electrolytic capacitors !

Can anyone help ???

Thank you - ALF

AL
Offline
alf
Bronze
Posted July 7, 2015 at 14:09 GMT
#2222294

Oops, correction

Circuit diagram is correct - I identified the wrong resistor !

Keep working on it, but it looks like 

4R4 = 60 ohm, specified as 82 ohm - a pain to get acess to !!

4R1 = 9.6 ohm, specified as 8.2 ohm, 1 watt

Any further inputs ?????

Cheers, ALF

AL
Offline
alf
Bronze
Posted July 9, 2015 at 15:12 GMT
#2222295

ok,

for those who are interested - here is an update:

I changed all electrolytic caps with either WIMA or Panasonic 105C caps on board 1 and 8 - done !

the eratic behaviour of the carriage/servo was caused be the hidden and missing spring of one of the lid bolts.

it went missing until I had to change 4R4 on board 4, lifted the board...and there it was :-)

further I managed to replace the burnt-out bulb in the shutter box with a 24V 40mA one - so far it works fine.

records play well again at this point in time and what is left to do is changing those tin-transistors and

hopefully restore the record-cleaning function - wouldn't that be nice ?!

I will keep you up-dated - thanks to all who are interested in that revival project.

ALF

L(
Offline
leeshep (archived2)
Bronze
Posted July 9, 2015 at 15:14 GMT
#2222296
Good work Alf. Glad it's all coming together.

Lee
mexking
Offline
mexking
Bronze
Posted July 9, 2015 at 16:24 GMT
#2222297

Good work and we like pics 🙂

Location: Mexico city

Retired
Printing machine technician
Restored various 1960-70 items
Rock and Roll music
Collecting Vinyl
Restored Jukebox Wurlitzer 1050
S(
Offline
Steveric (archived2)
Bronze
Posted July 9, 2015 at 17:33 GMT
#2222298

Well done, you did the trick, by the way It will be interesting to know how did you manage to change the bulb in the shutter box, as all we know the little black retain bulb piece looks like not so easy to perform...😮

 

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