Ah okay, thanks for clearing that up for me, my understanding was it was simply caused mainly by overheating, which in turn exacerbated other problems with the console, like the badly applied thermal paste and use of cheap parts.
Is the chip that's the problem the CPU or GPU? sorry if it's really obvious, kinda using this as a learning experience for electrical innards.

Also even though there's no permanent fix for RROD, which method is most long lasting?

Still looking for an answer for nylon vs metal washers too, although I've done a bit more research now and found that the claims that nylon washers could melt are probably unfounded; as the melting point of nylon starts at 190 degrees celsius, and if my xbox is running that hot I think the washers melting is going to be the least of my problems

And what do you do if you've fixed the RROD, and it occurs again? Throw the Xbox in the bin? I'm assuming applying the same fix again won't do anything.

The Falcon set died after 16 months only.

read that the jasper unit has less chance to died. is it true?

it can be revived.