I have this one, with old BIOS no power on, with this bios keeps rebooting, all coils have power (some constant, some coming and going as the device reboots), startup chime is reperating every 6 seconds as the device reboots

any ideas?

bios1: no backlight, can't see anything on display, no sound, no power on, not all voltages present
bios2: no backlight, can't see anything on display, reboot loop, startup chime every 6 seconds, all voltages present

There are two options but they prove their problem. All operations exist due to damage, nomeadamente no backlight. This option is firmware incompatible. There is no other firmware for this model, but there is no other firmware for a different model but we use it on my main board and on a 34" screen. We recommend you do a backup of your memories and test with the dumps of this model, which here are copies of all memories:
https://www.tecnicenter.org/lg-218/lg-34uc97-s-main-eax65923703-(1-0)-dump-bin-bios-eeprom-firmware-flash-spi/