White's 3900 schematic again

[Patrick]

And here !
http://www.md4u.ru/forum/viewtopic.php?f=61&t=2436

[ivconic]

And here !
http://www.md4u.ru/forum/viewtopic.php?f=61&t=2436

Same as my pcb.
Actually; i think all versions supposed to be the same, sharing same pcb.

[technos]

Same as my pcb.
Actually; i think all versions supposed to be the same, sharing same pcb.

From white's website there are manuals for three versions:
Coinmaster 3900 D Pro
Coinmaster 3900 D Pro Plus
Coinmaster 3900 DX Pro

My guess is the basic model does not have the meter and perhaps another model has VR2 trimmer installed to offer some further discrimination adjustment? Could you show how VR2 is wired on the PCB?

BTW turkish guy did not know how to read resistors. Beginners can make mistakes!

[ivconic]

There was not VR2 on my pcb, only holes...
btw...my 3900 was D Pro ... or it was D Pro + ??? Right now i can't remember..

[technos]

There was not VR2 on my pcb, only holes...

Yes, but the holes go somewhere. One side appears to go to R9 - where does the other side go to? It may be nothing, but I'm curious.

[ivconic]

I just finished redrawing pcb...

[ivconic]

[technos]

Ok, great job. I bet the circuit VR1/R9 etc form a filter circuit. VR2 could replace R9 for more accurate resistance.

Could you measure trimmer VR1 as it was adjusted when you pulled it out of the board? One side is shorted on the board.

[ivconic]

Ok, great job. I bet the circuit VR1/R9 etc form a filter circuit. VR2 could replace R9 for more accurate resistance.

Could you measure trimmer VR1 as it was adjusted when you pulled it out of the board? One side is shorted on the board.

I can. I will do that until evening. Than i will inform you here..
Cheers!

[Gervm]

I made two similar units several ears ago and saved some materials about it. May be it will be useful for somebody.

[Gervm]

Other side.

[Gervm]

Both sides.

[Gervm]

Circuit

[Gervm]

And modification.

[aft_72005]

Hi Gervm
It was good work , is circuit drawing with splan ?