# Unable to write to /sys/devices/platform/bone\_capemgr/slots file

**URL:** <https://forums.balena.io/t/unable-to-write-to-sys-devices-platform-bone-capemgr-slots-file/16930>\
**Category:** Product support\
**Created:** [June 24, 2019, 8:06am UTC](https://forums.balena.io/t/unable-to-write-to-sys-devices-platform-bone-capemgr-slots-file/16930 "2019-06-24T08:06:15Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![xginn8](https://avatars.discourse-cdn.com/v4/letter/x/8baadc/32.png) [@xginn8](https://forums.balena.io/u/xginn8)\
**Post date:** [June 24, 2019, 6:29pm UTC](https://forums.balena.io/t/unable-to-write-to-sys-devices-platform-bone-capemgr-slots-file/16930/7 "2019-06-24T18:29:34Z")

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Hi there @agaurav.

As noted in [this thread](https://forums.balena.io/t/enabling-pwm-on-beaglebone-black/8549/5) (and further [here](https://forums.balena.io/t/enabling-pwm-on-beaglebone-black/8549/15)), the `slots` file has been deprecated upstream and you need to enable overlays by manipulating `/mnt/boot/uEnv.txt`.

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_[View the full topic](https://forums.balena.io/t/unable-to-write-to-sys-devices-platform-bone-capemgr-slots-file/16930)._