When it RROD's press and hold the sync button, then tap the eject while holding sync in four times. Each time the ring segments will flicker. Follow the key to figure the secondary code out, 4=0, 3=3, 2=2, 1=1. Find out the secondary and then a fix can be figured out.
Xbox Xxperts says the following: "This error is caused by a cold solder joint under one of the RAM chips, mostly its the top ones, sometimes it can also be one of the solder balls under the GPU that lead to the RAM" https://xbox-experts.com/errorcode/E20/0110/
It may not be permanent but there are some fan speed mod xexs out there to assist with heating issues. Gorgeous kit by the way.
From someone who has botched many Xbox 360 repairs before, I would not recommend the oven method. Even with the tape or tinfoil, I have had caps blow up and render the board as an Oxford dictionary paperweight. I would not recommend the heat gun either as I have blown off resistors and rendered the board useless. The towel trick is a bit overkill, I stick 2 prongs in the back of the console to stop the fans from running. If the board comes back to life for a minute, you know it is a hardware issue, but I would not keep using the board. If you want to open it up, that will give you an idea of what is going on. I have had consoles that had no heat pads on the RAM. I have also had consoles with the cheap 8 screws XClamp replacement done, which warps the board, does damage, and is ultimately worse than XClamps. If either of these are the case, I would check out Xbox-expert's XClamp replacement, which is professionally engineered, and does wonders for cooling and keeping the motherboard erect. They also sell thermal pads for the RAM. I would also take a look at your CPU and GPU and make sure their thermal paste isn't caked, if it is, reapply some more. And, if you really want to give the console a long life, I would have it professionally reballed with lead solder, which expands as the motherboard warps and prevents cold joints. You probably already know I'm doing this. If the guy I hire is trustworthy and gets the job done, I will shoot you a PM and recommend him to you. Best of luck.
Dang, hate to see an XDK go to the bins because of RROD. Do ensure that the XDK is on "life support" now. X-clamp or reball or invest in cooling mods if required.
If you're talking about the nyko intercooler, it doesn't do shit other than make my console a couple degrees warmer. Damn fans on fans. What do you use? My Xenon's running at 80 degrees and it makes me nervous.
WOW 80!? dude, i have these dual fans that i soldered together to a board, and they literally just sit behind the console, and work together with the internal fans to add a total of 4 fans on the console, so the external fans are just forcing the hot air the internal fans are pushing out. but these don't use the xbox motherboard power. they use their own power source, they use a laptop charger power so they are like JET ENGINES! lol, no joke. i get 39-40C on both gpu and cpu ! cold, yes. loud. YES