I tried following this video on youtube
http://www.youtube.com/watch?v=GTBH29CmFHA

but my xbox wont overheat and display two red lights, does anyone know how to fix e74, ms cannot fix it cos, its modded

Thats not a guaranteed fix anyway, it usually works but you cant be certain. Anyway to make sure it overheats usually just disconnect the fans and make sure its in a fairly closed space. When I did my old one (which worked for about 2 months after then pooped again), I did the method where you put the case back on and wrap a towel around it. I left it for about 15 minutes at least before it overheated.

The towel trick is rubbish man... too dangerous for your xbox! You were very lucky it didn't get any damage and your got your problem fixed.

Anyway, the solution for E74 is simple and needs basic equipment and skills. Follow llama's tutorial

http://llamma.com/xbox360/repair/ring_of_l...x-clamp_fix.htm

to make the x-clamp fix if you didn't do it allready, and "bake" the xbox as it is said ont he tutorial.

If that doesn't work, you must use heatgun on HANA/ANA chip.

Good luck!