Fan won't spin in mainboard case

I just upgraded the mainboard in my FW13 laptop. I transferred my old working 11th gen intel mainboard along with the existing ram and wifi card (kept the audio card in my FW13) and a new NVME drive to the mainboard case.

I’ve tried powering up the mainboard with the 60 FW power adapter, as well as a 140W USB-C PD charger, but I can’t get it to boot into a bootable USB drive.

Here is what happens when I push the start button:

  1. The fan starts to spin very briefly (not even half a second)
  2. Simultaneously, the LED of my bootable thumb drive turns on for about a second
  3. Eventually (~10-15 seconds later), the side LEDs blink the diagnosis and post codes. All of the post codes return green. The diagnoses codes I list below.
  4. The side LEDs remain "on’ (white), but nothing happens for the few minutes that I watched it.

There are three diagnosis codes that return red. They are:

  • Battery connected
  • CPU deassert sleep S4
  • CPU reached S0 state

This is quite interesting considering that there is no display, touchpad, or audio board connected. As an aside, the LEDs blink incredibly fast. I had to record a video and then slow it down in order to discern each value.

Any suggestions on next steps for troubleshooting? I was incredibly careful while handling the mainboard so I don’t think I broke anything while making the transfer.

Take out the thumb drive and see if you can get into the BIOS to enable standalone mode. This will disable certain checks. Afterwards, see if you can boot from your USB.