Changed CMOS battery, motherboard had a brief fire

[cashlion]

Background: My buddy has one of these (https://support.hp.com/us-en/document/c03349236 )
Last March I put in a new graphics card (https://www.msi.com/Graphics-card/R4770_Cyclone.html ) for him along with a new power supply (https://www.evga.com/Products/Product.aspx?pn=100-N1-0400-L1).

A month ago the power supply craps out. After a month of arguing with EVGA (they refused to honor the warranty), my buddy says screw it and we get a new one (https://seasonic.com/product/s12ii-520/).

Put the new power supply in and hit the power button. Nothing. So I go to the store, grab a 2032 CMOS (same kind already in there), and pop it in. The PC turns on but part of the motherboard briefly catches fire in the half-second it takes me to cut the power (https://i.imgur.com/YJbqYQF.jpg; potato quality, sorry my crappy phone is all I have for pictures).

The smell of burnt metal is a great deterrent from turning it on again and I need some advice on where to go from here.

I am very much an amateur here and have no idea what caused this or if the motherboard is fixable (by us or by taking it somewhere) or if he needs a new one. His budget is too tight to build a new unit and EVGA yanking us around did not help either.

 

[Calvin7]

Power supply minimum requirements for the HD 4770 is 450 watts. Using inadequate power supplies can cause premature failure of the unit.

Cooling in the HP case may also be a problem. Excess heat caused by add-on components, running power supply at maximum output for extended periods of time may also lead to failure of electronic components.

It is important to use power supplies that meet or exceed system requirements and also have adequate cooling in your case.