upload code, arduino pro mini

I'm uploading this

void setup(){ pinMode(13,'OUTPUT'); }

void loop(){ digitalWrite(13,HIGH); delay(500); digitalWrite(13,LOW); delay(500); }

it works allright but I have 2 arduinos of the same kind that when I try to upload the code this message appears:

avrdude: stk500_getsync(): not in sync: resp=0x00

why?

pinMode(13,'OUTPUT');

Should be:

pinMode(13, OUTPUT);

You may need to press the reset button on the Mini Pro to get upload to work - try and time it right! It depends on what sort of USB->serial converter you use.

tried it all: correct the code and reset and as I said those are the only that I can't upload the code :(

Did you try holding the reset button down, then releasing it just after the IDE shows "Compiled xxx of 32xxx bytes"?

The other thing might be a mismatch between bootloader and the IDE trannsfer speeds. What you can do is re-install the bootloader - put on Optiboot - then select Uno for a board type. That was killing me on a standalone board I had, was selecting Duemilanove for board type after installing Optiboot, NickGammon had me use Uno and it worked great after that.

it is not a problem of instalation etc, for sure because I can upload the code in several arduinos but not in this one, is it broken?