I was reading your other thread about Kor not eating. I noticed that you have a coil UVB, that could be at least part of the reason why he is hiding. It also seems like a 100 watt CHE and 100 watt basking light is a lot for only a 40 gallon tank. Can you fill us in on the type of thermometer you're using and what the basking & cool side temps are? How old is Kor?
That's good that you replaced the UVB bulb, what one did you end up getting? Does your digital thermometer have a long wire & probe end? How long has it been since Kor has eaten?