I have come across many different ways to fix this nagging 3 red lights of death and of course it seems that many different pieces of failing hardware cause this. I have, on the other hand, created a way to fix this issue with one simple fix. REMEMBER: opening your 360 and doing this fix will void your warranty always make sure your 360 is out of warranty before trying.
Things you'll need:
12 pennies
Electrical tape
Hot glue gun
First you open your 360 up (see tutorial on how to)
Take out the mother board
Flip the motherboard upside down
Locate the 4 Ram chip that are black and around the GPU
Take 3 pennies, stack them on top of each other so it looks 3 pennies thick
With the electrical tap wrap the pennies so no copper is showing (make 4 seperate stacks of pennies)
On each ram chip use a very small amount of hot glue to stick the stack of wrapped pennies to the ram
now when you flip the motherboard upside down the pennies should sick to the ram
When putting the screws back in do not screw the black screws that hold the CPU and GPU- leave them off
Screw all the other screws on slow and tight and observe the inputs so that they match up with the holes in the metal casing (example USB ports, AV, Power etc)
You will notice the front USB ports seem to be just barely showing through the casing holes, thats fine
Make sure the fans are reconnected etc and test before putting back together
The reason this works as apposed to alot of other methods is because it kills mulitple birds with one stone
over heating-> there is now some space under the board so the board doesnt get as hot
bad Ram connection->obvisouly the ram is getting pressured back on to the motherboard
GPU/CPU issues-> with the released unneeded tension off the x clamps they dont seems to come unsolderd
I have waiting 11months to post this fix anywhere till i have tested it for a long period of time. I have done about 40 with this method and only on one did it fail to help.
Please post with reponses on how this worked for you, thanks