# GPIO stops working after several hours

**URL:** <https://mangoh.discourse.group/t/gpio-stops-working-after-several-hours/1273>\
**Category:** mangOH Red\
**Created:** [March 25, 2018, 5:26pm UTC](https://mangoh.discourse.group/t/gpio-stops-working-after-several-hours/1273 "2018-03-25T17:26:24Z")\
**Posts on this page:** 1\
**Showing post:** 21

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**Author:** ![nick](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/nick/32/1380_2.png) [@nick](https://mangoh.discourse.group/u/nick)\
**Post date:** [April 16, 2018, 6:43pm UTC](https://mangoh.discourse.group/t/gpio-stops-working-after-several-hours/1273/21 "2018-04-16T18:43:44Z")

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Hey @asyal,

I’ve been trying to get this issue to surface on our MangOH Red with no luck so far. I’m going to keep it running and see what happens. I had a theory that linked this issue to my host computer but unfortunately that contradicts my findings this morning.

Do you have any ideas in terms of anything that could trigger this problem? In terms of deviation from the MangOH Red reference design, our board has the following changes:

- Removed the `wm8944` audio codec
- Removed the `pca954x` i2c hub
- Removed the `sx150x` GPIO expander
- Removed the USB hub
- Removed the SPI over USB bridge
- Kernel modules modified to use i2c bus `i2c-0` for everything
- Removed code that probes for the `wm8944`
- SD card detection GPIO pin moved (with corresponding changes in Yocto)
- (Unrelated to hardware change) Enabled charging in an attempt to use the `ltc2942`

I’ve also put together a small repository to show some of these changes:

> **[nvandoorn/mangoh-red-kernel-changes](https://github.com/nvandoorn/mangoh-red-kernel-changes)**
>
> Contribute to nvandoorn/mangoh-red-kernel-changes development by creating an account on GitHub.

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