Followed guide. Used heat gun to warm entire motherboard and made circular motions over the 4 chips in the directed zig zag fashion. I read that some people did not heat it enough and had to do it over again, so I heated each chip for roughly 35 seconds each on low heat then went back and did them all again for 35 seconds each while still making sure the entire board was warm. Put it all back together and still the same YLOD. :/ I guess I'll try again in a week when I have more time. Maybe I will heat each chip for a minute instead.