Beogram 4002 not starting-tone arm not detecting vinyl

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saeedshamaee82@gmail.com Posted: Tue, Aug 31 2021 12:50 PM

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Hi guys,

I'm new in this forum and relativley new in B&O world, hoping you can help me out to fix up a BG 4002-5511

I recently bought a Beogram 4002, the owner's dad had it in his garage for many years.

It started working and could play records but tone arm was going down slowly, after I watched some youtube and read articles in this forum I lubricated the tone arm mechanism then tone arm started working smoothly, everything all good happy days. Just for a few days

suddenly one day device was dead, pressing start didn't do anything   the fuse was blown off, I replaced the fuse but it was still dead, no sign of life. After a few days testing the transformer and the voltage switch I came to conclusion that transformer was blown off so. I replaced it with a 25v AC transformer which is only one channel, I duplicate the wires and connect it to the board and the large resistor as per picture below. My engineering skills are vay below zero, so whatever I have done is self education and using experiences here in this friendly forum and also, a bit of help from a friend in UK via zoom, as still I'm stuck in lock down in Melbourne AUS .

Anyway, after replacing the power supply with this 24VAC 1A , now I could see some lights in the device which I couldn't see before changing the transformer.

But when pressing the start button it doesn't start the servo motor, I read in one of the threads that there is a part of circuit that will override the dis-engaged key next to the shaft and make the motor to rotate till the key is engaged again and shaft start rotating and move the tone arm till it reads a vinyl. But in my case it seems that part of circuit is not working ( which I'm not sure where that is?) is that correct?

When I have to manually rotate the shaft to engage the little key, then the light below the speed indicators turn on and start key works, but, this time tone arm goes to the centre and comes back till dis engage that ket again. it doesn't stop when there is a vinyl to read.

When I use the lowering key to lower the arm, arm goes down and now it can read the record and play the music.

So my issues are:

1. Start button doesn't start the drive shaft motor 
2. when I manually rotate the shaft, and press start, arm moves toward the centre but doesn't recognise the record and will go back all the way to turn off.

I have checked, the servo motor, it's not stuck I lubricated the tone arm mechanism and servo motor. Also, on day when I was pressing the start, a resistor blown off and was smoking, which I replaced it with a new one. ( I used the manual to and found it)

Is it because of the servo motor belt? as I read in one of the articles it may cause some issue?

any suggestion to where else to look or where to start?

is it the power supply issue as I didn't use two separate channels for similar to its original transformer.

I'd appreciate your help in advance. Thanks

Here is a video from how it is working right now and some photos that might help

https://youtu.be/lLc4zMEvjsg

https

I had trouble uploading images in the media section, so I shared my google drive folder 

https://drive.google.com/drive/folders/1UVhAQSYefb8OnQ7E2Ks7bKpWOFTafn1c?usp=sharing