# QC off bug **URL:** \ **Category:** Bug Reports\ **Tags:** quad-cortex\ **Created:** [December 26, 2022, 6:52pm UTC](https://unity.neuraldsp.com/t/qc-off-bug/9174 "2022-12-26T18:52:20Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![young1900x](https://avatars.discourse-cdn.com/v4/letter/y/c68b51/32.png) [@young1900x](https://unity.neuraldsp.com/u/young1900x)\ **Post date:** [December 26, 2022, 6:52pm UTC](https://unity.neuraldsp.com/t/qc-off-bug/9174/1 "2022-12-26T18:52:20Z")
**CorOS Version:** 1. QC still has a signal coming into the sound card after shutdown. The problem can only be solved after unplugging the power supply. I hope it will be fixed ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [December 26, 2022, 6:54pm UTC](https://unity.neuraldsp.com/t/qc-off-bug/9174/2 "2022-12-26T18:54:23Z")
Hi @young1900x and welcome to the community! You would need to provide some specifics with your setup. If the QC is powered off, it’s is not processing signals etc. Otherwise email [support@neuraldsp.com](mailto:support@neuraldsp.com) and they will get you sorted quickly. Also, noticed you indicated you are on CoreOS 1.0, please update your firmware to the most current version (1.4.0) as well. ---
**Author:** ![tjbassoon](https://sea2.discourse-cdn.com/flex020/user_avatar/unity.neuraldsp.com/tjbassoon/32/3363_2.png) [@tjbassoon](https://unity.neuraldsp.com/u/tjbassoon)\ **Post date:** [December 28, 2022, 12:50am UTC](https://unity.neuraldsp.com/t/qc-off-bug/9174/3 "2022-12-28T00:50:38Z")
Are you using the XLR outputs? The unit will simply do this. If you have XLR cables plugged in, and you turn off the unit from the power button, it sends a nasty squeal to the speakers. The only fix is to unplug the unit. This is known and expected behavior, and nobody is sure if it will ever be fixed (or can be). If you’re using USB I don’t know. ---
**Author:** ![MP\_Mod](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)\ **Post date:** [January 20, 2023, 8:17pm UTC](https://unity.neuraldsp.com/t/qc-off-bug/9174/4 "2023-01-20T20:17:11Z")