westfw:
If you can upload but not blink, it probably means that your pin mapping is not what you think it is.
Ie "pin 51" in arduino is not the same as "pin 51" on the chip.
http://www.pighixxx.com/test/wp-content/uploads/2014/11/mega.png
on this link is my diagram for my circuit i use isp for programing my board and i use mosi pin for blink
When i meassuring voltage on pin i have 0.5 V