I've been reading these forums for a couple of months but only just got round to registering because I've just noticed one of the chips on my UNO is a little bit melted. The small square chip to the left of the TX and RX LEDs, it looks like it's labeled ATMEL MEGA8[possibly a B]U2, but the left hand side is melted and the board around it is slightly yellower and shiny, I'm pretty new to this but I think it's delaminated, between the chip and what I think is a crystal (the silver rounded rectangle labeled SPK16.000Y).
I plugged it in to see if it still works, the ON LED does come on but I can't tell if all the pins still work and so on. Can anyone tell me what this chip does and what I could expect to happen if it's damaged?
I've only just noticed it so I'm not sure what caused it, but I was running a 7-segment display without any resistors yesterday (schoolboy error, research afterwards revealed that this was a bad idea), also I just put together a Proto Shield kit and the guide I used said to plug the male headers into the Arduino's pins then solder them to save time, could the heat from the soldering iron (which seems to have been sufficient to singe the board and delaminate it around every contact I've soldered...) have caused this?
I managed to get a photo of the damage:http://twitpic.com/4aop9g