The suggestion of testing the motherboard (some of the readers may not understand MoBo) separately is good, but be aware that some forms of plastic are well known to harbor huge amounts of static electricity. You might as well set it on a well combed cat. Seriously though, do be careful this way as static electricity can and will damage some circuitry. Perhaps the best surface is clean, dry wood. Such as a piece of scrap plywood or a cutting board. Additionally, cardboard works. If your home has nice thick rugs and you have been shocked by grabbing a grounded patio door, do yourself a favor and touch the kitchen or bathroom faucet before handling the computer innerds.
While you have your mobo out, look over the bottom of it as well as the top. Look very carefully. If you see scorch marks--such as from a grounding situation--it is probably toast. Motherboards are extremely sensitive. The later the board, the greater the sensitivity. This is due to sizing. As these products mature and gain in both speed and ability, they are still restricted by size. Notice that they have not become larger? Look how much performance and speed is built into something less than an inch thick as in a notebook (what I currently use here in Mexico) This is possible only because electrical and electronic standards as well as the processes used to create these miracles of our age have improved dramatically since my first 4.12 MHz 8086. In fact, the motherboard is smaller.
So now, rather than being more compact and hence less reliable, the reliability has increased dramatically! The problem is that the sensitivity to abuse has also increased. This is because the thickness of the circuitry has reduced as the closeness of individual lines to one another. Poke a skinny lil' pin into a modern mother board and it's likely cooked. Other than that, these things are tough, long lasting, and incredibly well designed. Like they say, practice makes perfect.
Gotta go, the dinosewer special is on the Discovery channel here in La Paz, and with my air conditioner in the shop, I need the pleasant distraction.
By, by..., and keep the shiny side up