Note do not atempt self repairs if u still have a warranty, if u do void ur waranty make sure u fully understand wat than means.
Do not atempt relf repairs if u cant even get the case open by urself n know that ul nd thermal paste ahead if time.

If its not the ANA its likely the GPU here is a fix.
I used 2 smal bits of hard plastic that i filed down to be the perfect hight so the heatsink touches the processors so it cools and at the same time the heatsink touches the lil pieces of plastic pushing the procesor chip down onto the board.
Remember similar to the ANA the GPU nds to be reflowed the GPU gets hot enough on its own and can get even hotter if u remove the AV cables but be careful, keep testin it with my method and leavin it to cool a bit inbetween tests is a gd idea.
Also try removing the GPU heatsink and pres on the corners(green areas not on the silver areas unles u want cooked finger tips) I found this to be the best method but hardest as it over heats quickly and gets realy hot,
so make sure the plastic or whatver u use wont melt and please dont use anything metal as it wil obiously cause a short.

If this doesnt work u wil have to consider over heating the GPU alot, keep ur fans on the CPU heatsink only keep it as cool as posible, do this anyway.
Make sure this is ur very last option before binin it or rebaling it(contact me for info) as it could burn out the GPU if u duno when is enough. (less info)