Parker D*1FH Series Proportional DC Valve Failures

We have experienced a high number of failures over the past 5 years. We have approximately 50 valves that have been in service for 10 to 15 years. The most common failure is with the electrical/electronics board. There is surge protection in the connector that is used to connect our control and power wiring. I can only assume the failures are due to a heating issue or an inferior component.

Would like to know if others have experienced issues with this valve type.

Thanks