Weird Monitor Problem

[DentyCracker]

I have never seen anything like this before, and can't seem to find any info on it. I have a LF24T350FHNXZA 24" FHD 1920 x 1080 75Hz FreeSync IPS HDMI LED Monitor that I bought off Newegg last year. It was connected via a KVM switch to my M1 Mac Mini and A107860K systems. Went to work one day and came home to the news that there hadbeen a lightning storm and everything had been plugged out after a particularly close flash of lightning. To cut along story short, the A107860K system doesn't POST and the monitor now only works when directly connected to the Mac via a usb c to HDMI cable (usb c on mac to HDMI on monitor). My theory is that the usb to HDMI cable has a higher output power. Any ideas?

[UtwigMU]

HDMI is all kinds of weird. I have work comp and work Samsung 49" and HDMI randomly decides on some days to not support 5k x 2.5k but only 4k x 2k.

Also there can be problems with HDCP (data encryption copyright protection) negotiation. It could be cable. I had a case with weird DisplaPort cable that would randomly not work with Thinkpad Dock and monitor. Do you have a chance to test monitor with new HDMI cable (the latest version HDMI you can get) and different computer?

[DentyCracker]

Yeah. I tried the monitor on other inputs using several known working cables.Only works with the Mac and only the USB C to HDMI cable. I suspect the HDMI port/circuitry is borked. A pity as it is ad ecent Freesync monitor. Paid USD117 for it. The mainboard for it costs USD65

[UtwigMU]

Ask around if there is a TV/Monitor service plays which does board repair.

[VJ]

Yeah. I tried the monitor on other inputs using several known working cables.Only works with the Mac and only the USB C to HDMI cable. I suspect the HDMI port/circuitry is borked. A pity as it is ad ecent Freesync monitor. Paid USD117 for it. The mainboard for it costs USD65

Could it be that the MAC uses a different default refreshrate through the USB-C to HDMI cable compared to the the PC?
There has to be some difference in the signal... but even if so then it does seem to imply the circuitry is borked...

(I have a monitor that no longer takes digital inputs: not on its hdmi, not on its dvi, only on its VGA... It used to be my father's, but his laptop lacks a vga port - he bought a new monitor and I currently use the old one connected to a desktop that has vga)

[Umfriend]

Could it be that the MAC uses a different default refreshrate through the USB-C to HDMI cable compared to the the PC?
There has to be some difference in the signal... but even if so then it does seem to imply the circuitry is borked...

Wow, that might be an interesting thing to try. I seems broke indeed but the MAC case does suggest there must be a way to make it work with some configuration of signalling.

[DentyCracker]

I think I am just going to use the opportunity to get a 32" 2560x1440 144Hz Freesync monitor in January with a R5 7600(X) $160 B650 mobo and 32GB DDR5 RAM. The Mac Mini needs a mobo change as its hdmi port is kaput as well as its LAN port

[Umfriend]

LOL. I read that as "My mobo is broke so I'll by a monitor". If I were in the market for a monitor, I would try to find a 16:10 one though.