# Ex Servo Upgrade: 9031 during home (Y)? Check your bumper

**URL:** <https://forum.avidcnc.com/t/ex-servo-upgrade-9031-during-home-y-check-your-bumper/3916>\
**Category:** General Chat\
**Created:** [November 11, 2024, 5:55pm UTC](https://forum.avidcnc.com/t/ex-servo-upgrade-9031-during-home-y-check-your-bumper/3916 "2024-11-11T17:55:07Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![berrianmtn](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.avidcnc.com/berrianmtn/32/4852_2.png) [@berrianmtn](https://forum.avidcnc.com/u/berrianmtn)\
**Post date:** [November 11, 2024, 5:55pm UTC](https://forum.avidcnc.com/t/ex-servo-upgrade-9031-during-home-y-check-your-bumper/3916/1 "2024-11-11T17:55:07Z")

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I started getting 9031 drive faults while homing after everything was working fine yesterday. I did update the VFD parameter and had success homing/parking.

Today the machine would not home giving the 9031 drive fault while doing the initial Y operation.

Long story short, the left bumper was installed such that the damper pin would not always go into the recess. This caused a big mismatch between left and right side and caused the fault.

Re-installing the bumper plate to ensure a clean alignment with the damper fixed the problem.