i bought this xbox 360 arcade (first version) of eBay (08/08/2010) for about £26 +P&P, that had the E74 error (i.e the one red light), with power supply and AV cable, when it came i opened it up and i found that the microsoft seal was still intact, but it still looked like it had been opened before, so it must of been repaired by microsoft at some point, but i could not see what had been done (i.e no X-Clamp fix etc.).
so after opening it up, i removed the X-Clamps and gave the GPU a heat-up with my old hot air gun , just for a minute or so, but didn’t do it at a hight enough temperature, but just enough for it to work for testing, after that i put the GPU heat sink back on, with out the X-Clamp (did the X-Clamp fix, i.e using bolts and washers), i hooked up the 360 main-board up to the power supply and AV cable, it started up fine, i then set about fixing some of the other problems that the 360 has (mostly over heating).
first i stuck a old PC CPU fan on the end of the GPU heat-sink (see picture below), then i soldered a molex connector on to the main-board (see picture below) to power the fan i put on the GPU heat-sink, after doing that i still found that the 360 was still not running as cool as i would of liked, i knew that the fans in the 360 were rated at 12 volts, so i checked to see just how much voltage was going to the fans, it was only 5 volts (i.e to keep the 360 quite), i needed to pump a bit more voltage into the fans, but enough to move more air, but try not to make it too noisy, i remembered that i had some PC fan reducers, for slowing down a fan inside a PC, i knew that they reduced the voltage from 12 to about 7 or 8 volts, so i took the plug off the end of one of them and soldered on a molex socket (to the 12 volt side of the molex socket) and removed the red wire from the plug on the 360′s fan, i.e the positive wire going to the first fan, in-line with the GPU (see picture below), basically bypassing the voltage going to the first fan coming from the main-board, but still letting the 360 control the second fan that is in-line with the CPU, as a result the GPU fan spins a bit faster then the CPU fan and therefor cools the GPU down a bit more, were the CPU is still cool enough, doing this has made the 360 a bit more noisy then i might of liked, but it is much much cooler now, i also decided to re-flow the GPU properly this time, by heating it up again with my hot air gun, but this time to the right temperature (round 220°c) and using some liquid flux to do the job right.
you can’t see it in the picture, but i stuck a small bit of card inside the fan shroud to help separate the air flow from the two fans, i.e so more of the air flow from the fan on the left (the GPU side) moves over the GPU heat-sink and the CPU does not hog all the cool air.
you might be wondering why i have stuck a two pence on one of the chips and a cooper pipe fitting on the other one, there really just cheep heat-sinks i made from things i found round the house, that might help with cooling the chips down a bit, all i did was smooth them down using a oil stone (for sharping knives), then put some heat compound on the bottom and used some bathroom silicone to hold them on the board.
i also bought a used/untested 20Gig xbox 360 hard drive of eBay for just £6 and a used/faulty controller for about £10 that i fixed and is working fine too.
xBox 360 Arcade with PSU & AV cable £26
Faulty Controller £10
20 Gig Hard Drive £6
X-Clamp fix kit £1
Liquid Flux £2
in total i spent £45
so far all seems to be working fine.
i’ve removed most of the mods that i did, like the extra fan on the GPU heat sink and my home made copper heat sinks, because i found that they didn’t really do much, where the higher air flow over the GPU heat sink and the better thermal contact between the GPU and the heat sink were the two mods that seemed to have the most effect in cooling down the xbox 360.
+++Update (12/09/2011) +++
about a week or so ago , i get the RROD and did a re-flow of the GPU again, i think it might of been when i re-applied the thermal paste on the GPU (some days before), i noticed that one of the washers (that i used as spacers) was a bit thinner then all the others, so i replaced it with one of the same size as the other, but i think doing so might of caused the GPU to be not as flush with the heat sink (as i think the main-board might of warped a bit over time) than it was before, i have now re-fitted the X-Clamps, to see if they might do a better job at keeping the GPU flush with the heat sink.
+++Update (14/03/2012) +++
i got the E74 error again, last night, so i did the re-flow as before, after i noticed that the small die on the GPU was a tiny bit lower than the GPU chip, (just like the same kind of problem i found with my PS3), so that might be why that side of the GPU fails first, so i used the same stuff i used on the RAM chips on my PS3 (heatsink plaster), on the RAM chip on the GPU, i'll see if it holds up or not, but so far so good.
+++ Upade (9/6/2012) +++
well it turns out that the X-clamps really are a load of ****, not that long after putting the X-clamps back on (see above) my Xbox red ringed again, so i decided to remove the X-clamps and go for the first solution that seemed to work, i.e like the above but using bolts and washers instead of the X-clamps to hold the heat sinks in place, i also stuck some little rubber feet to the bottom of the board,under the GPU and the CPU to push the board up more firmly to the heat sinks, all seems to be ok
+++ Update (15/8/20/12) +++
about a week ago, i turn on my xbox, all seemed fine, then after about 20 - 25 mins, it just froze, it would not respond to button presses, nothing, so i turned it off (by holding down the power button on the console) and when i turned it back on, i got the 3 red lights of death (RROD) and no display this time, this was the first time i had this error (before it was 1 red light with a E74 error on screen), but i didn't think to much of it and just did another re-flow on the GPU, same as i've done many times before, but that didn't do anything this time, after looking up the error light codes (by holding down the Sync button and pressing the eject button on the console, see this site http://www.llamma.com/xbox360/repair/Xbox-360-error-codes.htm for what the error codes mean), i found the error code for my xbox was 0110, meaning a memory problem, so i re-flowed the RAM chips too, NOTHING, i then re-flowed the CPU just to make sure, still nothing, i still got the same memory error (error code 0110), so basically i think thats it now, it's dead!
i think what might of happened was that all the times the GPU has been heated up doring the many re-flows, that may of shorted it's life so much it just died, but on the plus side, i but now i know that my method of using the heatsink plaster on the small die on the GPU seemed to of worked.