This reminds me of when I was helping a friend debug his home-built computer. Couldn't get a POST message out of it indicating why it wouldn't boot. After a while of searching, discovered it was because there wasn't a speaker connected to the non-existent pins for the speaker (there were no pins, just the soldering points for them). Once discovering that, used a multimeter to read the POST error - no GPU detected. Fun times...
Once I was introduced to an oscilloscope, I much preferred that. I bought a nice one off of ebay for about $60, and another peach of a scope from the pawn shop for $40.
