RESOLVED : the problem is solved.
No sound randomly , after startup , sometimes ,
I use the original power supply
It is a known issue which NDSP, as always, denies. I have had it with multiple units, a friend has and there was a thread once on this forum which since then has been deleted.
I forwarded it to support multiple times as well, which has lead to nothing but their standard answer: âunfortunately we can not replicate this issueâ.
On some forums this problem is described but there is no solution! Why? It is annoying for a professional musician!
I would assume it is a software related bug and therefor only solvable by NDSP. But as long as they arenât working on it, no chance.
Btw, itâs also annoying for amateurs 
I have this same issue with my unit.
the problem is solved. 
I found a solution that solved the problem for the moment. I put WD 40 SPECIALIST CONTACT CLEANER (in French: WD 40 NETTOYANT CONTACT ) in all the inputs and outputs and power supply: it is a âdry liquidâ that removes impurities and removes oxidation from electrical or electronic equipment) and everything works normally again. In summary: oxidation? dirt?
In practice I put the product in the sockets on the rear panel several times, also inserting a jack or the power supply socket with an in/out movement.
I found a solution that solved the problem for the moment. I put WD 40 SPECIALIST CONTACT CLEANER (in French: WD 40 NETTOYANT CONTACT ) in all the inputs and outputs and power supply: it is a âdry liquidâ that removes impurities and removes oxidation from electrical or electronic equipment) and everything works normally again. In summary: oxidation? dirt?
In practice I put the product in the sockets on the rear panel several times, also inserting a jack or the power supply socket with an in/out movement
Hey guys, I had this issue for several weeks now and got it fixed. It is an absolutely weired story but I want to share it with you.
Last year I played a festival with my second band. Our quad cortex had issues booting up. Just flashing footswitch leds but a dead screen. We had to borrow a quad cortex from another band which was kind enough to give it to us. I took our qc home and tried to fix it. Rebooting/restarting several times, resetting setting⌠no success. I removed the backplate to check the memory sd card. Removed and reinserted it. No success still no reboot. I picked the quad cortex up and put it on the front back edge at a slight angle and let it drop. Just a little bit to give it a small clap. And it worked. Since then there is no booting issue. I could not believe that it worked but it didâŚ
A few weeks ago from today, my own quad cortex (which is another device, not the one that had the booting issue) started to have issues with the analogue inputs 1 and 2. I tried everything mentioned above. I tried several power outlets (which was the fix for this issue a few months ago) but no success. I remembered that I fixed the booting issue by dropping it from a slight angle. I tried it with my quad cortex and guess what⌠It workedâŚ
What I wanna say with both stories: I do not know if it really fixed the issues but it has to be a huge coincidence if both quad cortexes randomly started to work again. In my opinion some issues are hardware issues and might have to do with the electronics inside the quad cortex.
This post should not encourage you to be violent against your gear⌠obviously. I want to share it with you so you can decide if you want to try that âbug fixâ for yourselvesâŚ
Greetings!
David
PS: Some other users said they had the same issues and they have send theirs quad cortexes to NDSP to get it to check. NDSP could not confirm the issue. Maybe the quad cortexes got some little claps during the transport and using some magic⌠it works againâŚ
This story does not seem to convince me that the QC is a high quality product. Hope Iâm wrongâŚ
Then again, I had to RMA my Fender Tone Master FR-10 because of a bad volume pot and other weirdness.
I guess every product can have itâs quirks. But twice with the same customer?
Iâve been struggling with this for a while now and have finally found a solution (well a work around anyway). Maybe 50% of the time my unit would power up in this state. with the same output levels as you have. Iâd then reboot the system and everything started working again. So frustrating, especially at gigs!
What I discovered is that it seems to be related to the noise gate on the input. I turned that off and now I have a 100% success rate when booting the system up.
Steve
Iâve been having this issue for a while now and itâs driving me nuts.
Neural support have been very slow to respond and all they do is ask me to send a video of the problem. Not sure how that helps, as itâs very easy to describe - there is often NO SOUND on start up!
Can you explain what you mean about turning off the Noise Gate on the input - do you mean you have to turn off the Noise Gate for every preset that has one on the input? Because for me thatâs most presets, which is a LOT of tweaking just to fix this problem, and we really shouldnât have to do thisâŚ
Unfortunately it reverted back to old (intermittently broken) behavior - I think my work around was just luck. I finally gave in and shipped it back for a repair. It should be returning later this week.
Steve
Was it inside the âwarrantyâ period?
I use inverted commas because there are some things I think should be covered within a certain period, like say footswitch coming loose or something, but a bug that is clearly affecting many users, and appears to have been introduced by a firmware update, such as this issue of having no sound, should be covered for life, or it will ruin NDSPâs reputation
The repair was covered. Shipping was not, which was quite expensive.
It got to the stage though where Iâd need to reboot 6 or 7 times before Iâd get an output, so basically unusable in gigs. Thankfully I have amps and pedals so didnât have to cancel anything.
Oh man - are you in the USA? And where did you have to ship to?
I donât get how they can cover the cost of a repair but not the shipping for it to be repaired?!
