Have I damaged the arduino?

I have been using the ARduino - with no problems.
I just tried the test "sweep" sketch to control a servo.

This is working fine - ie whenever i put power to arduino it successfully sweeps the servo.

My problem is that I cannot update the arduino with any different sketches.
(I have disconnected the servos - restarted etc etc)

Everytime I try to upload any sketch - however basic - I get error:
avrdude: stk500_recv(): programmer is not responding

I am guessing that I should have provided power to servo - externally (not through board) and this has caused the problem and a chip has blown?

ANyone any ideas?

Grateful for advice.

Andrew

try loopback test, without the servo connected

Also make sure Tools->Board & Tools->Serial Monitor reflect your Arduino and comm port.

Many thanks both - I have sorted it -
I am embarrassed to say it was the serial port selection had changed its mind and I was trying to write to the wrong port.
I was wrongly assuming it was something much more serious.

Thanks for your help - Much appreciated

Andrew