I purchased a Denon Prime 4+.
I bought it from the US, so there is no warranty or return option.
The problem is as follows:
The unit powers on and seems to work normally, but when I connect a USB flash drive or a hard drive, it doesn’t detect them.
Please don’t suggest trying another USB drive — I’ve already tried dozens of different flash drives and hard drives.
But that’s not the only issue. I also tried connecting my phone to it and playing a track. The track loads and starts playing, but there is no sound at all and no indication that there is any input or output signal.
I also tried connecting a microphone, but the mic on/off button does not respond at all — I can’t enable the microphone.
I sent the unit to a service center, but they couldn’t identify the exact problem.
They say the processor doesn’t see the USB devices, and regarding the sound issue, it’s unclear whether it’s the same problem or two separate ones.
There are no signs of burned components, no liquid damage, nothing obvious.
They say the board with the processor needs to be replaced, but they don’t guarantee that this will solve all the issues.
I would really appreciate your thoughts and advice.
Sorry you’re dealing with this. That’s a rough situation, especially without warranty.
I do not have a Prime 4+ and do not know anything about its internals. But what stands out is that all of these problems point in the same direction:
No USB devices detected
No audio signal from any source
Mic can’t be enabled
That makes it very unlikely that these are separate random faults. It feels more like a single core issue affecting how the unit handles inputs and audio, rather than something like “bad USB ports” alone.
If the service center is talking about replacing the main processor board, that at least makes sense given the symptoms … but I would be hesitant to spend serious money without some confidence it will actually fix everything.
Before going further, I would recommend:
Opening a ticket with Denon DJ support directly, even if it’s out of warranty
Asking if this matches any known failure patterns or if they can advise the service center
Checking whether a firmware reinstallation or recovery is possible, just in case it’s a software-level issue … which could explain the symptoms as well.
A partially corrupted OS or failed boot stage could allow the UI to run while lower-level subsystems (USB host, audio DSP) never initialize. This is a bit speculative, since I don’t know the internal details of Prime OS, but it’s one of the next things I would try …
“Just bin it” really isn’t helpful advice at this stage. You still have a working screen and UI, so it’s worth exhausting the official support route before writing it off. And it may be worth getting a second opinion, maybe from another service center.
Hope you manage to get a clearer answer … and if Denon or the service center gives you more info, post it here. Someone may recognize the issue.
I wish you good luck to get your Prime 4+ working again.
Hola, yo tuve el mismo problema, no reconocía nada en los USB ni el audio del bluetoo. El problema es el Modulo/Placa PCB Carrier y requiere la atención de un ingeniero de nivel 2, ya que hay que sustituir la Placa. En mi caso la tengo en garantía y me puse en contacto con Denon y se hicieron cargo del problema y me la repararon. Entre que la envié y me la devolvieron pasaron 3 meses, ya que tuvieron que esperar por la pieza ya que no la tenían.
Como dice el compañero, habla con el servicio técnico de denon.
You still have a working screen and UI, so it’s worth exhausting the official support route before writing it off. And it may be worth getting a second opinion, maybe from another service center.