Beogram 4004 Problem with " RUN OFF" switch (1TR16)

8 replies

hello,

i had a problem with my beogram 4004.

when push on the START button the arm goes over the record, and the pickup-arm goes down in the right position -

but the transport goes on.

Then you must push the LIFT button quickly, bevore the pickup arrives the record...

the service manual says, that ist a problem with RUN OFF switch (1 TR16) !?

is this a great repair? can it do by myself

much thanks for help, and sorry for my bad english...

 

greetings from germany

speedmaster

 

 

Could be a bad transistor.
Does the carriage continue to the center ?
Won't the carriage go to the right at all ?
If not, how do you get the carriage back to home position ?

Martin

hello martin,

thank you for your quick answer!

if there is not record on the deck, the funktions are ok, first 33 than 45 at the center carriage get back

to home position.

if there is a record on the deck, the carriage goes to the beginn position of record - the pickup goes down

but the carriage continue goes to the center. - the carriage transport didn`t stop

quickly push the lift botton, and the pickup goes up and the carriage stops.

push on the lift botton, carriage goes ahead and pickup goes down.

if push LIFT the carriage stopps, then you can push START, the carriage goes to center and home position, also you can push STOP, carriage

goes directly to home position.

when carriage is stoppt all funktions are ok ( << >> / < > slow-quick transport, start/stop) Lift up - pickup goes up are ok

- only Lift down V  - pickup  goes down and carriage goes to the center

 

i hope these are good answers for your questions

 

greetings bernd

I see.
Probably the tracking sensor/lamp/assembly that needs adjusting.
Maybe the interrupter has worked lose.
It should make the carriage keep up with the tonearm but only
just so, not run astray.
It's the diaphragm adjustment, page 3-5 in my service manual, I suggest
you try that before anything else.

With the tonearm hovering above the record;
If you press Lift  (to lower the tonearm and start playing) and the carriage starts moving already
before the needle hits the record, confirms the above diagnose.

Could also be an electronic fault, a cracked solder joint or something else, but the
above is by far the most likely.

Martin

Hi Martin,

the diaphragm adjustment is ok.

i think ist`s my mistake, i said carriage but i mean slide transport.

when push start, the pickup arm goes down on record start position but the slide transport

goes on with high speed.

it only stopps when you are push the lift botton, push it once more the slide goes with high speed

an needle goes down.

Maybe it`s a bad transistor in the electronik switch!? perhaps ist`s a possibility to exchange this one

 

bernd

Yes, I'm sure that the fault lies within the lamp/sensor or related circuitry.
You will have to measure around a bit, folow the sensor signal and see where it is disturbed.
Maybe a shorted sensor wire or a cracked solder joint at the main board edge connectors.

Martin

Hi Martin,

The beogram does very well...

I have looked at all of your last tips, everything was ok...

Then I`m starting the beogram without recordtable and "beltdisk" , push start - and take

the pickup-arm extremly left and right... the slide transport stopps!

Your first tip with diaphragm adjustment !!!!

So I take a completly new position of diaphragm !? - and it works.

 

Much Thanks to you! great job

 

Bernd

 

 

 

Good job !  🤒

Martin

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