# Turn for 90 not working

**URL:** <https://plc.pd.vex.com/t/turn-for-90-not-working/1902>\
**Category:** VEX IQ\
**Created:** [December 16, 2025, 7:12pm UTC](https://plc.pd.vex.com/t/turn-for-90-not-working/1902 "2025-12-16T19:12:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Maria\_Brinza](https://plc.pd.vex.com/letter_avatar/maria_brinza/32/6_22734026db12803ebb3e059622ac3534.png) [@Maria\_Brinza](https://plc.pd.vex.com/u/Maria_Brinza)\
**Post date:** [December 16, 2025, 7:12pm UTC](https://plc.pd.vex.com/t/turn-for-90-not-working/1902/1 "2025-12-16T19:12:42Z")

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Hello,

We wrote a simple code to turn 90. the robot spins forever. We replaced the motors and the brain and the smart cables. We still spin. Our drivetrain is correctly set up.

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<div class="post-metadata">

**Author:** ![Jimmy\_Lin](https://plc.pd.vex.com/letter_avatar/jimmy_lin/32/6_22734026db12803ebb3e059622ac3534.png) [@Jimmy\_Lin](https://plc.pd.vex.com/u/Jimmy_Lin)\
**Post date:** [December 17, 2025, 4:20pm UTC](https://plc.pd.vex.com/t/turn-for-90-not-working/1902/2 "2025-12-17T16:20:35Z")

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There are a couple things that you can do a part of debugging process:

1. Ensure the firmware is updated
2. Check if the robot can move forward and reverse straight. (Ensure not one motor stuck or wrong port)
3. Make sure in the device menu, the brain inertial is selected.
4. Ensure you start the robot on a flat surface so it can be calibrated correctly.
5. Change the turning velocity to 10% to begin with and then tune it to a higher velocity.
6. Swap out motor or brain to a different one to see if it works.

Please let us know if any of these solved your issue.