Hi @doriancussen
Seems like a problem on the mainboard given that you have no display and also no menus either but it could also be the power board as well.
The "...seems to still light up in some way..." appears to indicate that the backlighting in the screen is working so some parts of the power board are still working at least.
Bit of a vague answer I know so the best I can suggest is to open the monitor and visually inspect the boards for any obvious component damage i.e. bulging or leaking capacitors and any burnt out or heat stressed looking components.
Unfortunately I couldn't find any schematic diagrams for the boards, you may have better luck.
Here's the disassembly procedure that may help.
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
1