Welcome to our Technical Information Pages!



Understanding How and Why





  • Camera displays an ‘Overheating’ warning - usually followed by a shut down.  This can happen as soon as the camera is turned ‘On’ or after several shots.
  • One or more camera functions (AF, exposure, Light meter, Flash, etc) are out of calibration or are intermittent.
  • This problem might happen before or after the Main PCB is replaced!


Possible Reasons:

  • Temperature Sensor failure in one or more circuts  (such as:  Memory Card, Shutter, CMOS, AF or AE Units). Or a connection failure between the Unit and the Main PCB.
  • Main PCB failure.
  • Data Corruption.
  • EEPROM Corruption.



  • Start by saving the data files ( .crm and .dig files ) from the original Main PCB if possible. Do this using the Canon Service Adjustment software for that model.


  • Open the Temperature Plugin in your Canon Service Adjustment software and check the temperatures in the different Units.


  • Replace the .crm data file on the original or new Main with ‘Known Good Data’ - SPT can help with this if necessary.  You can do this without any disassembly.

If this solves the problem you have corrupt data and you can use the know good .cmr data file.  BUT .. you should check the calibration in other camera functions (such as:  AE, AF, Shutter)   


  • Test the Temperatures again using the Temperature Plugin.

If the temperature is still badly out, its the Units temperature sensor / connection issue.  You should especially check the connection between the Unit and Main PCB.


If the Unit Temperature is only out by a few degrees, the EEPROM is probably corrupt.  You may need to send this to Canon for adjustment.