Fan runs at 100%

I recently modded my oled switch successfully. It was fine for about a week and then started booting straight into OFW bypassing hekate. I suspected the D0 adapter that came with this chip, the black colored one with no anchor points on the sides. I took it back apart and redid the adapter which got the modchip back working but now when it boots into either original or atmosphere, as soon as I see the Nintendo logo on the screen, the fan kicks in at 100%. The console is reporting that at idle, it never gets over 27C. I have replaced the original cooling fan and symptom remains. Old thermal paste removed and replaced with fresh each time the console has been disassembled. Any ideas of what to look for? Any tips would be greatly appreciated.