I have an old socket7 motherboard that i have not tested yet because i need some specific capacitors first. It has about 3 capacitors that need to be replaced one already exploted on the bottom- But next to those 3 caps there is a mosfet, a fairchild FDB6030L mosfet.

When i looked at the board i noticed that the green PCB changed its color a little bit near the mosfet, what should be green..has more of a brown like tint color on the pcb.

Mosfets can even operate at a very high temperature, but is it normal to reach a temperature where it actually changes the color of the pcb?

I have seen other motherboards that are working and the mosfet gets extremely hot.
and i have seen on videocards from the TNT2 era, where the pcb is blue or yellow, and on the back of the card the pcb changed its color because of heat where the mosftet is located in the front

is there a rule for replacing a mosfet with a different one on a motherboard? (for example capacitors should be same UF and greater voltage) i was looking around another FDB6030L but cant find it on my local shops.