Uno - RX blinks three times, pause, blinks once, pause, avrdude error

I have an Arduino Uno, running 64 bit Vista with Arduino 0022 and going through USB. I've had the Uno for nearly a year and this is a new problem.

When I try to upload a new sketch after compiling completes, the RX light blinks three times, there is a pause, the RX light blinks once, then I am given the following error (verbose):

avrdude: Version 5.4-arduino, compiled on Oct 11 2007 at 19:12:32
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

System wide configuration file is "C:\Users\Owner\Desktop\Arduino\arduino-0022\arduino-0022\hardware/tools/avr/etc/avrdude.conf"

Using Port : \.\COM4
Using Programmer : stk500v1
Overriding Baud Rate : 115200
avrdude: ser_open(): setting dtr
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Recv:
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: Send: Q [51] [20]
avrdude: Recv:
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

avrdude done. Thank you.

It is not the first time I have uploaded this sketch to the Arduino and probably the hundredth time it has been in the circuit it was in when it began failing.

I have tried it with other USB ports and with another computer running Windows 7 and I have the same problem.

It does still pass this 'loopback test':

Wire a jumper between pin 0&1
Select the correct serial port on the Arduino menu
Open the serial monitor
Hold down the reset button while you type something and press send on the serial monitor
What you type should appear in the receive window

I keep hearing about re-burning the bootloader all over this forum but I don't know how to do that or if it is the solution and I'm starting to think that it's an over-prescribed treatment.

Any help would be greatly appreciated.

The next step is to remove all connections and shields. Connect the lonely Arduino to your computer. Try to upload.

Okay, I guess I forgot to specify, that is exactly what I have done and the RX blink is what happens.

Because of the conclusion we are drifting towards, I want to make absolutely certain the problem is not something simple...

Using Port : \.\COM4

...when you performed the loop-back test, did you use COM4? Has your Arduino always been presented as COM4?

Edit: Spelling corrected.

Haha your response is cryptic and ominous.

It passes the loopback test when using COM4 and it always seems to present as COM4 now... but I can't say if it always has. I'm sure it is COM4 because of the passage of the 'loopback' test but also because when I disconnect the Uno COM4 disappears from the Serial Port menu.

Does the RX light blinking pattern indicate anything useful?

Does the RX light blinking pattern indicate anything useful?

It's an indication that the USB-to-serial converter is working correctly; which is good news. If you have a board with a replaceable / in-socket processor, the rest of the board is very likely still usable.

Unfortunately, I think you're left with two possibilities: 1. Bootloader is corrupt. 2. Processor is damaged. In either case, you're going to need another processor (or board).

So I have the plug-in processor version (here: We are sorry but you have encountered an error ) ...

Can I replace it with this: http://www.cutedigi.com/product_info.php?products_id=4576 ?

KRA2008:
Can I replace it with this: http://www.cutedigi.com/product_info.php?products_id=4576 ?

Yes.

It is not a big deal but, if I were in your shoes, I’d get them to confirm the processor is an ATmega328P. You may also want to determine which Uno bootloader they are using. I think one of the versions has an amnesia bug.