No display and weird led flashing

Hello
I’m new on mutable (and in electronic). Just bought and assembled the shruthi1.
I’ve 2 differents problem with the machine.
first, the led flashing well, but not in any conventional order. For example when I press first switch, the led 1 never turn ON, and When I turn the change mode rottary, I have led turning on randomly.
Second. I connected the screen, and unfortunately it’s stay blank. I have tried to turn the R21 screw but nothing happens. I tested with my ohm metter (hard for me to speak about electronic in English ) in the “bip” mode to check the circuit. I got bip on first and last point, looks like I have a short circuit, but Can’t undestand how can be possible.

If you have any idea, please let me know.
thanks

ps: sorry, hard for me to explain in english when it’s already hard for me to explain in french.

> I got bip on first and last point, looks like I have a short circuit, but Can’t undestand how can be possible.

It doesn’t seem anormal - if the screw is turned all the way in one direction, the 2nd pin of the trimmer will be at the same potential as the 1st or 3rd pin. As long as the display does show characters or a line of blocks, the trimmer is incorrectly set. Turn it in the other direction until the middle pin approaches 0.5V-1V.

“Turn it in the other direction until the middle pin approaches 0.5V-1V.”

middle pin of the screen ? and where can I get the ground ? (sorry i’m an early bird)

Middle pin of the trimmer.

Ground points are labelled GND - there are several you can reach on the control board or on the filter board.

ok, looks good, screen switched on :))
just have to replace the 8x1 pin that I cut to short, and let’s try the sound.

thanks for your support.