I've read through several threads here and elsewhere on this subject however most of them seem to be solved by 'it suddenly started working' so I was not able to really apply anything to my situation.
Currently I am attempting to upload the blink sketch to an arduinoMega using an uno as a programmer. I am attempting this in preparation for a self made board that will be using a stand alone Mega2560 chip and 16MHz crystal. If possible I would like to perform all programming operations via the 6pin header (MISO,MOSI,RESET,etc). From what I have read this should be possible.
At the moment I am able to load a sketch directly into each the uno and mega boards via the arduino IDE. so I know both are working boards with bootloaders. I've trippled checked the wiring between the uno's pins 10,11,12,13,+5,GND to the Mega's programming header as well as the physical pins on the chip and edge of the board.
Additionally I am using an external 5V supply as suggested elsewhere on the target board. However I am still getting: avrdude: Device signature = 0x000000. This is being attempted by using the 'upload using programmer with the following settings: Board: ArduinoMega2560 Processor: Mega2560 Com Port: Uno (loaded with ArduinoISP sketch) Programmer: Arduino as ISP
I have also read into changing the boards.txt file. I have attempted this as well using Notepad++ but did not see a difference either way. I assume this is just for setting the bootloader, which I have not actually done since this is a working Mega board which I can still load sketches directly into.
Is there anything else I could be missing here? I will be attempting this on another computer as well just in case my IDE is acting up.
Edit - A fresh install of the IDE on a different PC produced the same results, programmable directly but not via the Uno.