I fixed a RROD xbox 360 about a year or two ago by simply taking it apart and cleaning/reapplying the thermal paste.
Now I've received another RROD xbox 360 and after applying the new thermal paste and partially assembling it (case is still open, fan + DVD ROM plugged in) I pressed the power button with a screwdriver and 4 red lights flash twice, then 3 red lights flash constantly.
What does this mean? I heard of 3 red lights but not 4 red lights twice, then 3 red lights... or is this normal for a 3 red light problem?
Anyways, I've ensured all the screws are tight on the motherboard.
I'm not sure. I found out you can spit out error codes by pressing the 2 buttons on the front of the motherboard. With nothing hooked up but the dvd rom and the front board, if I plug in the power cable and press the buttons to get the code I get code 0020. That apparently is "unknown" but many have fixed it by messing with the pressure of the heatsinks. there's bloody pressure sensors in this thing? For real?
I don't think that is it. I mean any inside components may be loose, your PSU cables especially. Plus your outlet cables. Just check all the wires and make sure they are in good.
What makes you so sure? The power supply lights up green when I turn on the xbox. 4 lights flash twice, then 3 lights flash forever. I found out how to get a diagnostic code from it and got code 0020, which apparently means an issue with the heat sinks on the GPU/CPU. They have fresh arctic silver and I re-used the old x-clamps.
According to microsoft, 4 lights flash with no a/v cabled. I got 4 lights twice (because I don't have cables attached) then the 3 lights. I get an error code that many have said is caused from heat sink pressure issues.