Does it happen with any other card?
It could be a faulty connection between the Vga ramdac output on the board, the Vga connector on the board or the cable.

Thanks for your answer !

Yes all others cards are ok with the same cable / display.
Do you know how i can check the ramdac ?
I will try to connect the card to the TV with the svideo port and see if something is different.

You can try to short circuit this inductance (L):

I indicated the purpose of the inductances approximately. First of all, you need short circuit HSync and Vsync inductance. And if i not mistake, short GND inductance. Maybe this will help.

Thanks for your reply !

I've shorted the three last inductances (HS VS and Ground) and no changes.

Could this behaviour come from the chip himself ?
In fact, even at boot, when the card display the BIOS version, i can see there is something wrong : lack of precision for the caracters.

I've been unable to find something to correct this problem...i think it will go to trash can 😒

Thanks for the replies !

parhelia512 wrote on 2019-10-06, 16:06:

I've been unable to find something to correct this problem...i think it will go to trash can 😒

Thanks for the replies !

Did you manage to resolve this issue? I'm interested because mine is doing the same thing! 😞