yeah a good reball on the gpu and cpu chip need it 1444 and up There is no "4" in the error codes. Four lights is a "0" go back and check your code again. but i think a good reball will help but it can be used for spare parts though
I don't think a reball would fix this one. Best thing to do would implant new CPU and GPU chips on it. However I told him to bin it because it's too expensive and not worth the bother.
Eww the dreaded E34. Paddy your chances of fixing that with a hairdryer and a repaste are well ... non existent.