When a reflow isn't enough?

[dj_deknoi]

Hello there, ive got an xbox thats do something thats new to me, But it keeps doing it which is more annoying..
Anyways I have a HDMI xbox which is nice, But when I turn it on within 3 seconds the Back Fans go mega fast then 2 lights appear "over heated", but its not hot, its blowing Cold out and its just turned on...
I fixed it afew times before with a Reflow, then it works nicely, then randomly "days or hours" it will turn on to the same Fast fan to 2 red rings... I imagine its a cold Joint under the CPU or GPU but I dont know, can anyone help me in identifying what it is...
Im not sure its a cold joint because every xbox ive fixed when its a cold joint it gives 3 rings.. This gives 2 rings and Fast fan in seconds, Its like Turning xbox on without Heatsinks there.... So im not 100% sure what is it...

 

[hotspot]

Damaged temp sensor me thinks. There is a component one the underside (under where the chips are) of the board for each chip that, if remember right, if its damaged it cuts or changes the way the xbox detects its temp causing it to think its overheating... Cant remember which one, but i would check under the board just in case there is an obvious damaged one.

 

[dj_deknoi]

Well i know its not over heating, its Solid Cold, So faulty Temp sensor sound about right, But how do i fix this? I read something about cutting the temp sensor trace But how? It points to something on the xbox board but I dont understand, could someone help me please on this? I know the xbox works amazing other then the stupid thing overheating when its not...