Msi B450 tomahawk max(DOES NOT WORK)

MSI B450 TOMAHAWK MAX motherboard. Cannot get into bios menu or do anything after turning on, no display output, GPU works tested in different system.
Of the EZ Debug leds, cpu light is constantly on when trying to start. Cpu fan keeps spinning but no POST, red CPU light is on indefinitely.
Tried a different PSU even though current PSU works with other motherboard, tried three different CPUs which all work in another system, 7 3700X, 5 2600, 5, 3600X.
Ram also works, tested in different system. If I try to start without RAM, DRAM light of EZ Debug leds turns on. Tested motherboard with it resting on cardboard to have no short circuits.
Cannot flash the system with the Flash Bios Button. After pressing flash bios button, usb drive flashes around ten times, then stops, flash bios led blinks three times, then stays constantly on (no flashing).
Tried two different usbs drives, one with 8 gb and one with 16 gb capacity. The 8 gb drive is usb 2.0. Formatted both drives as MBR and FAT32 with Rufus. No success. Tried creating a smaller partition of 2 GB, using windows diskmanager. No success.
Ofcourse for the above steps, the bios file was renamed to MSI.ROM, tried different bios versions, no success. Every time same symptoms after pressing the flash bios buttion (usb drive flashes around ten times, then stops, flash bios led blinks three times, then stays constantly on (no flashing)). I used the flash bios port for every attempt mentioned here. Tried flashing the BIOS without any components attached to motherboard, no success. Tried flashing the BIOS without any components attached to motherboard, no succes. 24 pin and 8 pin cpu connectors were attached to motherboard when trying to flash. Tried resetting CMOS before flashing, no success.