Motherboard repair

Welcome Newcomer! :)

"No display" can be caused by a lot of things, but we need a lot more info:
Model Numbers and/or links:
MOBO {motherboard}
GPU {graphics card}
PSU {power supply}
RAM

If your MOBO has an on-board GPU then more than likely the MOBO needs to be replaced, or if the GPU doesn't need extra power from the PSU then the GPU MTL needs to be replaced, but if the GPU requires power from the PSU then either the GPU or PSU may be the culprit. If you pull the GPU and "observe" a successful startup then you can R/O the MOBO.

Good Luck!