Author Topic: Few issues  (Read 361 times)


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Few issues
« on: September 28, 2020, 09:39:54 AM »
Hey there,

I have just finished my preen fm2, and it looks like it is working quite well, not perfect but well, but i have encountered a few problems and confusions during assembly.

First of all, i bought the vandaal DIY kit with blue metal case and blue screen (i have no idea if it is OLED or LED) so this was my first confusion.
The PCB looks like the R5 one and it is white, but i had a few components which was different looking frome the ones in the build instruction.

The USB stick from the kit was not working and i have replaced it with other one which works fine. The preen boots, I can hear the sound, midi works as well, but i have issues with screen.

It is flickering, when changeing parameters, and when i connect midi, it flickers in sync with the midi clock.

It is powered via usb cable.

I Also have some parts left which I didnt know what to do with really. Especially with the metal plate, and i was unsure what to do in this step:

If you have a PCB revision R5d, you’ll have an additional resistor named Oled on the right of the above picture .
Populate it with a 22 ohm if you have an OLED display or shortcut it with a resistor pin if you have a LCD display.
So i puted a 22ohm there.

Can You help me somehow?


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Re: Few issues
« Reply #1 on: September 28, 2020, 09:20:29 PM »

If you have the metal case, it's an OLED display.
For the components, you should ask Van Daal Electronics directly.

The 22 ohm is not required with the blue OLED (only the yellow one).
I don't think it's responsible for the flickering, but you can try to shortcut the 22ohm manually just to see if that makes a change.

The flickering is not normal, i can only advice you to double check all your soldier points related to the display specially around the 22ohm resistor as it's the main current.
You'll find a schema here :


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Re: Few issues
« Reply #2 on: September 29, 2020, 07:25:44 AM »

Yes the Blus screen makes odd stuff if you put the 22ohm there. Shortcircuit the 22ohm resistor, then you are fine.

The USB stick. Did you plug it to your computer and saw it doesnt work?
I load the preen folder on the stick before I send out the kit. So they are checked before delivery one by one.

The metal plate is to shield the OLED screen.
See this forum post for pictures.