122770 06  18-09-2007  25 
 
Error:  Calibrator does not cool or heat sufficiently or 
is slower than specified (ATC-125 only). 
Error message: 
- 
 
Likely cause:  Solution: 
Set the calibrator to –90°C 
Check voltages on test pins: 
 
Between GND and 24V           >23V 
Between GND and TC_Well    1,4V+(6.20 mV/°C x T) 
Between GND and  PWM        >1V and <2V 
Between GND and TC_SMH   0,8V+(6.20 mV/°C x T) 
Between GND and SAFE         >4,5V 
 
Defective Power PCB 
Set the SET temperature to 125°C. On the 
Power PCB measure the voltage between 
test pin 24V and GND. 
 
If the voltage is less than 23V, pull out 
CN103 and re-measure. If the voltage still is 
too low, check fuse F3 on Power PCB, else 
replace Power PCB. 
 
If pulling out CN103 re-establishes the 24V, 
the Stirling Controller PCB is defect. 
 
Defect safety 
thermocouples 
If “Safe” is low, check  “TC_Well” or  
“TC_SMH”. If defective replace the sensor. 
Broken ribbon cable 
If the PWM signal is missing, the 34-poled 
ribbon cable between Main Board and 
Power Board is broken or the Main Board is 
defect.