# \[Solved\] Peripheral power / brownout / bootloader / PSM **URL:** \ **Category:** Cube Autopilot\ **Created:** [3 May 2019 13:27 UTC](https://discuss.cubepilot.org/t/solved-peripheral-power-brownout-bootloader-psm/748 "2019-05-03T13:27:23Z")\ **Posts on this page:** 1\ **Showing post:** 31
**Author:** ![Anubis](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/anubis/32/334_2.png) [@Anubis](https://discuss.cubepilot.org/u/Anubis)\ **Post date:** [14 May 2019 01:53 UTC](https://discuss.cubepilot.org/t/solved-peripheral-power-brownout-bootloader-psm/748/31 "2019-05-14T01:53:46Z")
My experiments: Attached a load that pulls ~0.8A on the I2C 2 port. Ran trials that consist of powering the Cube Black, waiting ~5 minutes for the current to be limited (or not), then un-power the Cube. Copter 3.5.7 NuttX: Problem appeared 37/50 trials. Copter 3.6.2 ChibiOS (and later): 0/30 trials. Copter 3.6.8 with above PR: 0/10 trials. It seems that, at least for this specimen, the problem had already been solved by Copter 3.6.x, I guess it gets hidden by different timing on ChibiOS boot, so I can’t really test the PR with this particular Cube. We have blue cubes on hand, I’ll see if I can reproduce it with them. To me, the mystery is why this suddenly started happening. We’ve flown 3.5.7 since its release and only had this issue appear lately, which suggests a hardware change. It won’t be an issue once we finish migrating to 3.6 (assuming the PR fixes it), but the sudden and inexplicable onset was a bit jarring. Glad @Morso was able to dive into it deeper than I could. --- _[View the full topic](https://discuss.cubepilot.org/t/solved-peripheral-power-brownout-bootloader-psm/748)._