What would cause my 5890 FID to state it is at 300C, but feels only warm to the touch?

I have a 5890 GC running ASTM D2887, simulated distillation. It is equipped with a FID and recently we noticed the FID won't light. Flows are good and gases are good. Looking at the setpoint/actual reading, it states it is at the correct temperature (300C), but we are able to touch the FID mount comfortably, which is unusual. We have other GCs whose settings are at 250 and very much feel too hot to touch. I have confirmed the insulation around the FID is still there and hasn't wasn't touched before the issue started. I have switched out the cables coming from the board to the detector and this did not resolve the issue. I checked all the Fuses, they are all good. Does anyone have any suggestions on what to check next? Thank you. 

I will also add, that after switching out the heater lines for the detector, it took about 20-30 minutes to even get to it's maximum heat, by feel. The reading on the GC claims it took only a couple minutes to obtain a temperature of 300C, but at this point, the detector was room temperature. 

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