# Sleep won't wake up

**URL:** https://community.particle.io/t/sleep-wont-wake-up/14871
**Category:** Troubleshooting
**Created:** [August 29, 2015, 4:45pm UTC](https://community.particle.io/t/sleep-wont-wake-up/14871 "2015-08-29T16:45:50Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![MisterNetwork](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/misternetwork/32/2880_2.png) [@MisterNetwork](https://community.particle.io/u/MisterNetwork)
#### Post date: [August 29, 2015, 6:23pm UTC](https://community.particle.io/t/sleep-wont-wake-up/14871/2 "2015-08-29T18:23:34Z")

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I did a little searching around, and if I understand correctly, waking from deep sleep is like powering it up after it is off, so doesn't the code stop executing after System.sleep(), never executing the rest of the code - sleeping will never be true.

\*\* Update - check here..

> [@Deep sleep and variables](https://community.particle.io/t/deep-sleep-and-variables/13500/9):
>
> Hi @itayd100 which version of the firmware are you using. If it was 0.4.3rc2 it could have been a problem as LTO was enabled due to which sleep was not working as expected. If you have the option of testing locally, please try the firmware’s develop branch: [https://github.com/spark/firmware/tree/develop](https://github.com/spark/firmware/tree/develop) A new release for use with Web IDE should happen in the next week.

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