Hi thanks for the info, I tried the loop back instructions on the UNO I was having trouble with, nothing was echoed back via the serial monitor when testing the UNO also tested another board a USB DROID ( to check I was doing the test correctly) which worked fine. D13 LED does blink/flash a few times when reset is pressed after the test ie. jumpers removed, From this do I draw the conclusion that the UNO is dead or is there something else that can be done to resolve this issue?