I was given two 360's that both had E74 RROD errors. I fixed both of them using a heat gun detailed by another guide. I know this is by no means a professional fix however both consoles were free.
I now want to keep them running as cool as possible without leaving the case off constantly since these consoles are at a high risk to RROD again.
Below are some of the mods I did to help with heat. My goal is to keep the console as "stock" looking as possible.
To start off I did the 12V fan mod so both rear fans are at 100% constantly
I then used a dremel and cut out the rear fan guard mesh so that air could better be pushed out the back. I did not cut the plastic outside part as I want the console to remain looking stock.
Since the GPU was the problem in the first place, I added a 45mm fan on top of the secondary gpu heatsink and used a 3-pin Y connector to attach it to the primary fan connector
Lastly, I wanted to allow air to better enter through the front near the gpu fan, so I used the interior metal mesh as a template and drilled new ventilation holes through the top of the case.
Because I used the metal as a template, this almost looks stock after I sanded the new holes.
So what do you think?