Hi rdunnill,
Earlier, I mentioned that I tried putting one of my own graphics cards that I knew worked from a different computer in to my cousin's computer. The graphics card was a PowerColor Radeon HD 5450. It's a budget card too ($15 after rebate from Newegg) but I don't know if it is highly compatible or not. Unfortunately it didn't work in my cousin's Dell computer's PCIe X16 slot. I had the same issue that I had when I tried the GeForce GT 610. The motherboard behaved as if the card wasn't there.
What is it about the Sapphire 6450 that makes it highly compatible? For example is there a feature in the specs of graphics cards that I can watch for? I'm kind of derailing my own thread but I need to buy something better than the Intel HD 3000 graphics that I've been using in my own computer.
Unfortunately his computer has acted funny because of too much dust on more than one occasion. If the motherboard is damaged from overheating I'm curious exactly what on the motherboard is damaged. I understand it's probably not worth the trouble to fix the damaged component on the motherboard if something is damaged but I still wonder. I would guess the northbridge or southbridge chip is damaged.
I tried to find a replacement motherboard just to see what the price would be but I haven't been able to find anybody who is selling the motherboard. Part of the problem is I'm not sure what is the motherboard's model number. Maybe I missed it but unlike other Dell branded boards this one doesn't have a "Model: <code or name>" printed on the board.