Both units was send in to Denon Service Germany. After test they answered the following:
*In the event customers experience any issues with their products within the warranty term, under their limited warranty they will receive a free of charge warranty inspection with our service team. If a manufacturing defect can be found, goods will be repaired or replaced with a like-for-like item, at the sole discretion of inMusic - the manufacturer. If a fault cannot be found by our service team, goods will be returned as “Fully Tested – No Fault Found”. For more information on what is covered under warranty, please refer to the safety and warranty information booklet provided with your product.
In this particular instance, our service team have carried out a warranty inspection on your X1800 mixer and SC5000M players. All units were inspected by our qualified service engineers. When running their tests, all of your products were tested using our internal diagnostic app which tests all functions of your PRIME setup; and will indicate if there are any hardware failures. Following this, our engineers tested your set up inline with the fault descriptions originally provided and carried out subsequent soak tests to monitor performance and ensure the products were working consistently.
During these tests a fault was found with your X1800 mixer. This will therefore be replaced with a brand new one as a warranty replacement. No faults were found with your SC5000M’s and thus the results of our manufacture inspection is that these units are Fully Tested – No Fault Found.
These units will be returned accordingly and should be back with you before the weekend as requested.*
in the follow up I wrote:
It goes without saying that I’m pretty upset about the way, the hassle and the constant delays.
It borders on cheek how the whole case is handled. Please escalate it to the Denon headquarters because this can´t be in their strategy, pls report to me. Denon DJ Support is quite not helpful, except obviously in preventing customers from getting their rights. I contacted the dealer directly instead of Denon. This took place immediately after purchase/delivery in November. Look at the screenshot retailers answer.
What should the customer do, if the dealer contacts Denon to fulfill the replacement as a solution instead of carrying out the guaranteed replacement themself?
For sure, it is Denon’s task to solve this kind of inline with the respective retailer, instead of shifting this back to the customer for the sake of simplicity!!!
In regard to the SC5000m players, the error list was emailed as a file attachment and was also attached to the devices as a printout. Denon’s behavior indicates that no complete check has obviously taken place, because some of the errors are clearly hardware-based and require manual checking. Were individual components of the players replaced in this context? These errors include the following:
see above list
A test program can only provide an indication of error diagnosis, but no definitive evidence. Have the devices been subjected to a stress test lasting several hours under load? in this respect, I ask for the detailed test protocols and log files to be sent.
As professionals, we can´t appear with any faulty units.
If Denon continues to insist that the manufacturer does not feel responsible, please inform the retailer of this, and that they are responsible to fulfill the customer rights. Clarify this and send the players to them for immediate exchange. I still demand my customer rights.
In terms of the SC5000m some errors also occur when the players are directly connected to each other or even in standalone operation without an Ethernet cable connected, it is technically impossible that these errors are caused exclusively by the X1800 mixer. I guess a hardware error in the players, possibly hairline cracks in circuit boards, or even defective soldering points. These nonsensical discussions are completely idiotic because due to the product liability the retailer has an obligation in any case and I will claim my rights. Thereafter, the retailer will assert his rights against Denon once again. So why unnecessarily complicating it?
As mentioned before, these units will be used by professional Artists in public. So far we have not published any negative posts/comments or videos about any errors.
We hold up the Denon DJ flag in public and especially under the Artists. It´s not easy to get artists to switch from Pioneer to Denon or even play on Denon DJ Gear for one night/gig. Most insist on their technical rider, calling for Pioneer setups only. To support us event organizers, Denon has to ensure that all the devices do not cause any show stoppers in public traffic, otherwise, it is impossible to go with Denon devices in such pro environments. As these showstoppers occur during performances, they are extremely uncomfortable for everyone involved, especially for the performing artists. Hangin´ or resetting units are a nightmare for any of us, needless to mention the frustration.
and received this answers:
Your case has already been escalated to the highest point of inMusic Europe; and I am the most senior member of staff for service related cases. I am very sorry for the issues and frustrations you have experienced to date.
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As I’ve previously advised, warranty action can only be taken against the original goods purchased – and this is what has happened. I also advised that based on the fault descriptions provided, it would be unlikely that we would find an issue on all 3 units. I also confirmed that replacement units would only be provided on goods that were found to be faulty.
A fault was found on your mixer; this has been replaced. No fault was found on your players; these have been returned accordingly.
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If you have any further grievances or wish to pursue any further action in accordance to your consumer rights, then I must kindly refer you to your place of purchase; though I’m unsure as to what further action they would be able to take, as your consumer rights would only be valid against goods which are faulty – and we’ve already replaced your mixer.
Answers are from February 2021. Units are still not back from Service. I spend a lot of money for useless, faulty equipment. Everyone thinks for themselves and how such errors can be caused by a mixer if the lan cable is not connected to this unit or another mixer like DJM900 was used. For me it sounds a bit like: we exchange the crappy mixer and we will see whether the customer keeps his mouth shut. Needless to mention that these units were bought in November 2020 and the case is open since December 2020.
At our events I forced them to play with it. Voluntarily or reluctantly everyone had to deal with it because I only set up denon devices in the dj booth. 
