ARDUINO UNO : DOES NOT COMPLETE UPLOADING TILL RESET

Using Arduino IDE 1.x
1

My Arduni UNO was functioining perfectly well until recently. Whenever I try to upload a sketch it keeps on 'UPLOADING' for ages, it only stops once reset button is pressed. There is no error in compiling. This happens with the simplest of sketches. Can someone guide me please, is it due to some minor error or do I have to replace the board.

regards

2

Which Rev of Uno?
Later Rev's have a diode from Reset (anode) to +5 (cathode) to catch spikes on the reset pin that made the chip think it was going into high voltage mode. If you have an earlier Rev, try adding a 1N4148 or similar small signal diode between the Reset & +5 pin on the power header.