# QC doesn't work ... sometimes with no reason !
**URL:** https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880
**Category:** Bug Reports
**Tags:** quad-cortex
**Created:** [August 4, 2026, 12:05pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880 "2026-08-04T12:05:25Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 4, 2026, 12:05pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/1 "2026-08-04T12:05:25Z")
Hi,
I have a recurring issue with my Quad Cortex. Regularly, no sound comes out at all. I’ve thoroughly checked the input/output levels, etc. I notice that the tuner works correctly, however no guitar sound comes out, either through my cab or through my headphones, and when I play guitar, there is no input signal LED activity at all.
I also connected the QC to my Mac to use it as an audio interface, and that doesn’t work either (I’ve correctly configured my Mac’s output settings).
I recently ran into this issue right before a show. I powered it off and restarted it several times, and it eventually started working just a few minutes before the show.
Is this a known and identified issue on your end? Has someone already experienced that?
Thanks for the help
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### Author:  [@Gtarguy](https://unity.neuraldsp.com/u/Gtarguy)
#### Post date: [August 4, 2026, 12:58pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/2 "2026-08-04T12:58:10Z")
Hi I’ve had this also but whether it’s the same thing I don’t know! But do you have a midi controller connected to the QC and I have to wakeup the controller and make sure it’s in stomp mode or whatever tap a button and then the expression pedal works and the volume works… But I do have signal reading on inputs and outputs just no sound until I get the board setup type of scenereo
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 4, 2026, 1:46pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/3 "2026-08-04T13:46:05Z")
Thanks for the interest. I don’t have any midi controller connected. It works perfectly … until it stops working ! And a few days later it works again.
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### Author:  [@xush](https://unity.neuraldsp.com/u/xush)
#### Post date: [August 4, 2026, 2:05pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/4 "2026-08-04T14:05:00Z")
you need to contact [Support@neuraldsp.com](mailto:Support@neuraldsp.com) it could be your I/O board dying. They’ll want videos if you’re able to duplicate the issue.
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 4, 2026, 3:13pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/5 "2026-08-04T15:13:09Z")
I’m waiting for their answer atm. I thought it could be the input 1, but the tuner is perfectly working which is strange
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### Author:  [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)
#### Post date: [August 4, 2026, 4:29pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/6 "2026-08-04T16:29:38Z")
Are you using the OEM power supply? If not, what PS are you using? These output issues have been known to stem from power supplies in the past or as @xush stated, worst case it could be a defective I/O board. Have you tested to see if USB audio works? Example, do you have the ability to test using a cell phone playing a backing track or any audio?
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 4, 2026, 8:47pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/7 "2026-08-04T20:47:38Z")
I use the original power supply.
I’ve tried the USB. It is recognized by my computer but once again, no output sound
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 4, 2026, 8:51pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/8 "2026-08-04T20:51:07Z")
Also, the input 1 level is always on -18.1 db
And the headphones output is waving up and down like if there is sound … whilst there is no input or output sound
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### Author:  [@h2loh](https://unity.neuraldsp.com/u/h2loh)
#### Post date: [August 4, 2026, 10:59pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/9 "2026-08-04T22:59:48Z")
Return it if you can and buy another one if you are still interested, something is wrong.
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### Author:  [@MP\_Mod](https://unity.neuraldsp.com/u/MP_Mod)
#### Post date: [August 5, 2026, 3:11am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/10 "2026-08-05T03:11:07Z")
I agree, contact [support@neuraldsp.com](mailto:support@neuraldsp.com) to determine the issue. Hopefully a factory reset will resolve but it’s best that support logs the issue and guides you through the necessary diagnostics including a factory reset or next steps if needed.
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### Author:  [@iNX](https://unity.neuraldsp.com/u/iNX)
#### Post date: [August 5, 2026, 5:36am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/11 "2026-08-05T05:36:42Z")
Hello, I’ve also the same problem randomly.
Excatly same symptom :
- No sound at any outpout
- Input 1 work (tuner)
- Output 1 level on settings screen display output
A restart can solve the problem, but if you didn’t have time while giging can cause a really inconvenient situtation
It’s not a hardware problem if we have same issue
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 5, 2026, 9:22am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/12 "2026-08-05T09:22:47Z")
The support doesn’t reply so far. Do you have a solution on your side to make it work correctly again ?
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### Author:  [@SelfTitledLP](https://unity.neuraldsp.com/u/SelfTitledLP)
#### Post date: [August 5, 2026, 1:03pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/13 "2026-08-05T13:03:41Z")
How long ago did you message support? Usually they respond within a couple days.
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 5, 2026, 1:41pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/14 "2026-08-05T13:41:36Z")
a couple of days 😉
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 6, 2026, 8:58pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/15 "2026-08-06T20:58:01Z")
I still don’t have a feedback from @Neural atm and i’m bummed!!!
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### Author:  [@xush](https://unity.neuraldsp.com/u/xush)
#### Post date: [August 6, 2026, 9:45pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/16 "2026-08-06T21:45:50Z")
If you contact a Mod they might be able to check on that for you
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 6, 2026, 10:15pm UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/17 "2026-08-06T22:15:38Z")
> [@xush](#):
>
> Mod
thanks ! i’ll try to find mods 🙂
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### Author:  [@littlespaceman](https://unity.neuraldsp.com/u/littlespaceman)
#### Post date: [August 7, 2026, 8:08am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/18 "2026-08-07T08:08:22Z")
I had a similar issue and they repaired mine under warranty - they also replied quickly, so you need to continue to chase them about this
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### Author:  [@h2loh](https://unity.neuraldsp.com/u/h2loh)
#### Post date: [August 7, 2026, 8:16am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/19 "2026-08-07T08:16:03Z")
If you are within the return period, I suggest you do so. Way less hassle.
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### Author:  [@xetiennex](https://unity.neuraldsp.com/u/xetiennex)
#### Post date: [August 7, 2026, 8:37am UTC](https://unity.neuraldsp.com/t/qc-doesnt-work-sometimes-with-no-reason/22880/20 "2026-08-07T08:37:05Z")
The support team just replied me. As I’m out of warranty, they provide me a 300€ quote for shipping in/out (50€) + technical intervention.
I’m annoyed because this is a known problem of the QC users and is it really me to be in charge of that?! …
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