[weblacky]

While you seem to have things in order I guess I'd have to ask...the suddenness of the failure leads my mind to a possible power issue, not IC.

I mean, you cannot read it (all 0xFF) and you cannot flash it in place...but it was working just a few hours before. Wouldn't it do these things if it were being fed improper power or being shorted in some way? Before you go into this pulling and replacing...can you do a basic multimeter diode check on the VCC and other legs of the chip to see if you have a short with the board out. After that, if you can solder a wire to test point on the chip for VCC, plug it BACK into the system, and power it up and then take a voltage reading using the wire, then you would know you have good power to that chip.

It's just really really odd that you suddenly cannot do anything to the chip...a small passive (Cap, resistor, etc) dragging down the "local" 3V rail near the chip makes more sense to me than a chip suddenly not working at all with no warnings.

Let us know what you find, good luck.