Anet A8 board fried

Hi
I'm new here and relatively new to printing.
I recently bought an Anet A8 and I'm happy with it, now it's had a few printed upgrades. I fitted an inductive sensor to the back of the carriage to try out auto leveling but the sensor fouled on the bed power connecter. I had previously soldered the red and black direct to the board but theft the thermistor wires on the white plug. The red and black were looped over the plug causing the sensor to snag, so I figured I would quickly unplug the thermistor wires alowing the red and black to fall below the plug. As I removed the plug the temp on the lcd changed the "def" and I expected it to return to norm when plugged in again but instead I got a bed temp reading of 243 degrees. This number does not change, plug in or out, if I short the plug terminals it goes up to around 700 degrees. I have flashed the board with Skynet and the problem is still there so I figure the board is fried.
This has put me off buying another Anet board and im thinking of trying a ramps board, is it a reasonably easy proccess to swap from Anet to Ramps?
Bob

There are only three components in the bed temperature monitoring circuit. Resistor R37, capacitor C43 and the bed thermistor. Unplugging the bed thermistor while turned on would produce the "def" that you mention on the display, but there is no way that this action would have damaged the control board itself.

Where I suspect that the damage arose, was when you plugged the bed thermistor back into the bed with the power still turned on. What most people do not realise, is that on a number of these control boards (including the A8), when the bed is turned OFF both of the bed power connections have +12V present on them. The control board turns the bed ON by dropping one of the connections to 0V. It only needs a momentary contact between one of the power pins and the wrong wire of the bed thermistor connection and you have put 12V through a 5V chip.

It is never a good idea to unplug and re-plug connections with the power turned ON as this can unintentionally trash things, even on a Ramps board. You shouldn't blame the board for something that you did, but shouldn't have.

Just to add that what you have probably fried is the analogue to digital converter on the processor chip that converts the analogue input to digital. If you were able to flash the bios afterwards then the rest of the chip is probably working. However, you will still need to replace the board.

Thanks for the repy and you are right, I shouldn't blame the board for my stupidity.
I have ordered a ramps kit, inluding the bigger lcd screen and it means I won't have to fight with the 5 wobbly buttons.
Bob