When I try to upload any sketch to my arduino uno r3, the code compiles, the board resets and the RX light blinks 3 or 4 times.I have nothing from the TX light.
The uploading progress bar in the IDE stucks at it's end for a period and then gives me "avrdude: stk500_recv(): programmer is not responding" 10 times.
I've done the loopback test and it works well so, what should i do ?
thanks for help.
yes, it has worked before. ... uncorrect bootloader or something,,...
Does the last program you successfully uploaded write anything to the serial port? If you just run the Arduino (no upload attempt) with the Arduino IDE's serial terminal open, can you see that output? It's pretty hard to damage the boot-loader without actually writing a new, bad one to the chip.
If the current program seems to running but not writing to serial when it should, a likely cause of upload failure is the code in 16U2 processor (or the chip itself) that handles the USB to serial conversion; it's the square 32-pin chip between the 16 MHz crystal and USB connector. Its firmware can be re-loaded - search here for how to do that. If the chip itself is damaged it is probably not worth attempting a repair.
Update: Is the +5v pin on the power header (left edge of the board, if the USB connector is pointing up) reading 5v? You'd expect the output pins to read 0v, 5v, or be noisy if they are floating. A steady 1v sounds strange. At this point it would be worth trying this board on another computer, and another board on your computer, and see which one fails.
