Pin 13 is HIGH and it blockes Bootloading

Long time ago I noticed the bootloader in my Arduino Uno Rev. 3 Original doesn't working, and then I tried to burn bootloader on Arduino and it doesn't worked (Invalid Signature: 0x000000), I also tried bootloading atmega328p on a breadboard and I got same error, then I bought an atmega328p, I can burn bootloader on a breadboard but can't on my Arduino Uno, I think because the L led (pin 13) is always high (also its high when the Arduino Uno doesn't have a microcontroller) and one of the pins used to burn bootloader is 13. I must learn where the L led (and pin 13) connected to but there's too many via. But I now the Atmega16u2 is working well because I can upload codes to my Atmega328p on a breadboard. Where the Pin 13 connected to?

The led is driven by an opamp. You can find a link to the schematic on the uno's product page.

It is normal that the L led is on on real uno; both my originals do while the sparkfun redboard (without opamp) doesn't.

This does not mean that the pin is actively driven high by the microcontroller. It's behaving more like an input pin with internal pull-up.

That said, if you've abused the power rails of the board - usually the first part to go is the 16u2. On clones that don't use the 16u2, the first part to go is the aforementioned opamp. If this has happened, the opamp will become very warm or hot while the board is powered (this is an easy test), the LED will always be on, and pin13 won't work correctly because all pins of the opamp are near-shorted to ground. Since the opamp also controls the power switching circuit, that won't work correctly either.

DrAzzy, my arduino is original and I’m sure 16u2 is working and I powered Arduino for 5 mins and the 8 pin smd IC (I think its op-amp because it’s at the same place as LM358 on clone Arduinos) is still cold

sterretje:
The led is driven by an opamp. You can find a link to the schematic on the uno's product page.

It is normal that the L led is on on real uno; both my originals do while the sparkfun redboard (without opamp) doesn't.

This does not mean that the pin is actively driven high by the microcontroller. It's behaving more like an input pin with internal pull-up.

The L led was off before I get the error, and I didn't said the HIGH signal is coming from microcontroller, and if this isn't a error , I must able to burn bootloader on Arduino Uno so It's an error and it blocks the communication of Atmega328.