About seven or eight months ago my 360 E74'd. Usually that would mean tossing it in a coffin and sending it off to Microsoft but that was a no go as my warranty was void. So I elected to fight it. I purchased an X Clamp replacement kit and installed it. Oh happy day, the damn thing worked again... for a while. Not to long after the fix I began to get pinkish scanlines. I was able to fix them by completely removing my board from the casing and adjusting the tension on the GPU. The problem soon became a recurring one and I elected to drill the holes under the GPU screws bigger so I wouldn't have to take my board out of the metal casing. That worked for a while and my 360 stayed out of its casing for quite some time. The E74s hadn't stopped being a problem just not a frequent one. I discovered that unplugging the fans and letting the console over heat would allow it to boot again. After a while I got sick of the console being naked so I drilled four holes in the plastic casing to access the holes I had drilled earlier. The console regained its casing and worked for a while. I'd get an E74 every once in a while but in general I was able to play my games. Then it began E74ing fairly frequently. It lost its case again so I could over heat it. Again I grew tired of it being naked so I decided to add a switch so that I could turn off the fan from outside the case. That was tonight, check out the pictures.

Have you tried a reflow?

I don't know what that is. So no.

maybe this would help:
http://www.solder.net/technical/reballing.asp

That poor xbox 360...

Its its own fault.

Try to do Llama's reflow trick. To do full reballing, you will need rework station + balls + flux + skills. I don't think you have anything of these, so do Llama's tutorial trick.