Beogram 3404 Speed runaway issue

3 replies
M(
mx5ido (archived2)
Bronze
3 posts
Posted April 14, 2020 at 21:22 GMT
#2136893

Dear Friends.

My Beogram 3404 spins very fast like 78 rpm or much more.

The electronic speed control (servo) has problem somewhere in the PCB. the motor get the maximum voltage all the time.

 I don't know if it's bad capacitor or IC or something else. I pulled out the motor and plugged it

on my other Beogram 3404 (I have 2) . on the other turntable the motor working flawlessly is it should.

So, the motor is not the problem.

The speed buttons are not responsive.I  have some knowledge in basic electronics

but I do not want to take risk and would like to get information if somebody here had experienced

in this  repair. (the belt is new and set properly in the motor pulley)

Many thanks.

DI
Dillen
BronzeModeratorFounder
12777 posts
Posted April 15, 2020 at 06:18 GMT
#2136894

Most common is a wrong or worn down belt.
If the belt is slipping, the motor will accellerate to easily and the electronics will allow it to sync on double speed.

Other possibilities:
Cracked solder joints on the controller PCB
Oxidated speed setting trimmers (remember there are three)
Some other electronic fault

Martin

M(
mx5ido (archived2)
Bronze
3 posts
Posted April 15, 2020 at 09:28 GMT
#2136895

Dear Martin.

 

Many thanks for your answer.

As i said before, The problem is the electronic control and the belt is new.

For ow yet all the other thing you mentioned found without problem.

I started to dive into the PCB. I had replaced capacitors. Now I'm checking all the resistors and transistors.

From  there I will proceed to the IC.

I'm hopping to find the bad component and save this turntable.

 

Thank you.

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