TX/RX not lighthing up + Uno not showing up in device manager

Development Tools IDE 1.x
1

Hi,

Two weeks ago I received my two arduino UNO boards, which worked flawlessly as of this morning.
Since both were working I experimented a bit with one of the boards and tried to control accurately a servomotor (tried to have it move a few degrees each 10 seconds and repeat all over again)

I must have done something wrong at some point because now one of my UNOs is not recognized (it doesnt show up in Device Manager) but the other one shows up perfectly. I can upload blink to the working UNO without any problem, so this removes any pc & hardware problems, which leaves me with the unrecognized UNO being the problematic link in the chain.

I tried the solutions in the troobleshooting faq, but nothing solved it. I tried holding the reset pin which had no effect but having the "L" Led flashing 3 times quickly.

Until I find a solution I will experiment with the second UNO (which doesnt leaves me stranded) but since one of the UNOs was supposed to go to a friend of mine, I'd really like to fix it.

Any suggestions? If any more info could prove insightful I'll gladly take pictures / describe more in details.

(OS used: Win7-x64)

2

try to reprogram the 8u2 firmware

3

Fantastic. For some reason I could not upload "UNO-dfu_and_usbserial_combined.hex" so I had to select "Arduino-usbserial-uno.hex" (Otherwise, Flip would give me the "Out of address" error..!)

I can now upload new sketches!

The TX/RX lights seem to flicker a lot less though, I will investigate that later on.

Thank you for your help! It's really appreciated.

-John