Not sure about the 650W thing - I checked on pcpartpicker and it says 250W, and when I entered my system build in there it estimated 423W total.
I've had a look in the BIOS in order to set the primary graphics adaptor.
There are two options for initiate graphic adapter: PEG and IGD. Seeing as it was previously set to PEG. I've tried setting it to IGD then booting with monitor connected to graphics card but nothing doing.
wattage isnt everything.. lower wattage psu are sometimes built with inferior material hardware which causes to give low amps in 12v rail used to power gpu
do one thing.. get the system tested with an 80 plus bronze 650w psu...