RC7 Controller IPM Troubleshooting

Modified on Fri, 09 Feb 2024 at 12:29 PM


Learning Method to Troubleshoot Bad IPM Cards in RC7M Series Controller:


An IPM Card is the component responsible for generating the pulse width modulated signal (PWM) to move a servo motor (essentially a Servo Driver). IPM is an acronym for “Intelligent Power Module”. IPM cards vary in size depending on the wattage motor being driven. The RC7 controller can recognize the size of the card that is installed.  The controller will not allow the robot arm to be operated if an incorrect size card is installed in a slot. Reference the top cover of the controller to identify the correct IPM map for the controller.   



Some RC7 controllers use multiple IPM cards of the same size. In the event a RC7 controller has multiple IPM cards of the same size, the cards can be swapped from one slot to another slot. If a controller is experiencing an error, its possible to identify a suspect IPM card by moving it to a different slot which uses the same size card. If a IPM card is responsible for the error being generated, the errors generated will change and “follow” the suspect card. 


Ex. A RC7M controller configured for a VS068 series robot is experiencing a J1 power module failure. The card can be identified as the source of the error by powering down the controller and swapping the IPM card from slot 1 to slot 2. When the controller is powered back in, if the error generated is now J2 power module failure, the card has been identified as bad and will need to be replaced. 


If a controller does not have 2 cards of the same size, a card can be confirmed as bad by using a new IPM card from spare parts. 


If the error doesn’t follow the card, the problem is likely deeper in the controller and a spare controller should be installed. 


A cards size is noted on the label of the card as pictured below. 

Tools and Parts Needed

#2 Phillips Screwdriver

Full Sized Teaching Pendant

Step by Step Guide

Step 1

Identify what joint is experiencing the error by referencing the error code. 



Identify if a controller has multiple cards of the same size by referencing the chart to the left, or by checking the cover of the controller. 

Step 2

Power down the controller and remove the power cable from the controller. 

Step 3

Remove the top cover of the controller by removing 8 screws

Step 4

Remove the suspect card by removing 2 screws. 

Step 5

Remove the card from the controller. Replace with new card or exchange with card of the same size and secure with the screws removed in step 4.

Step 6

Reattach controller cover and secure with the 8 screws removed in step 3.

Step 7

Reattach Power the controller on. Determine error status of controller.

If IPM card was swapped with another slot, did the error follow the card? If so – replace card. 

If a new IPM card was installed and the error is still generated, please investigate repair of the controller at a Denso Service center. 

Next Steps:

  • For repair options in the Americas please contact support@densorobotics.com
  • For repair options outside of the Americas, please contact your local Denso Service Center. 

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