Please help repair Fluke Ti27 thermal camera

[f14]

Hi all,
I have problem with my Fluke Ti27 . it stuck in 60-100oC level ( manual/ auto mode are same)and poor accurate
example 300oC soldering iron it show ~90oC ( it raise up to 90oC and stuck in this temp even soldering iron is hotter)
anything below 100oC can not get a image
So have any Idea?. inside the camera is clean, no burn/blowup something. the FPGA Cylone IV is hottest component~60oC. DRS U3510 sensor is ~45oC (after power on 15min )
thank you!