Prime 4: Headphone Mix knob controls both Headphone mix AND X-Fader contour

Hi there - I am having an issue very similar to this gentleman:

Basically, the headphones mix knob controls both the headphones mix AND the X-Fader contour, while the X-Fader contour knob does not have any effect at all. It appears to be a bugged assignment in the software. I have updated to the most recent firmware (1.5.2). Please advise, thanks.

All on Prime 4.

So with the previous firmware (1.4.x) you didn’t have this flaw?

It was on 1.3 or something - it was not working on that either. Upgrading did not fix it.

Seems unlikely to be a wiring issue, or an issue with damage as both of the functions are bound to the headphone mix knob, so maybe it’s a software assignment issue?

hey there guys is your prime 4 second hand mine was and in the end i found out that my unit had been bumped/dropped on the front and it had damaged the little pot that controlled this function a replacement circuit board cured the issue

cheers jason

If the knob didn’t work that would be fine, but the headphone mix controls both which makes no sense? seems like a binding issue.

With your issue, did the headphone mixer knob control the contour like mine does?

Yesterday I checked my Prime 4 with Fw. V1.5.2 and the crossfader adjustment knob works as it should and I have no problems with those listed in this thread. So it shouldn’t be a firmware defect.

As I’ve been unable to get even a modicum of help from Denon (which is extremely disappointing given I’ve switched here from Pioneer only recently) and there are absolutely no reliable support people here in Australia, I’ve had to disassemble the Prime 4 myself to see what the issue is. Thankfully it does not look like a huge one, but I’m posting images here if anyone can give advice. It appears the X-Fader knob has become dislodged from its position on the PCB. I’ve tried resoldering it but it did not make any difference.

Looks like I might need a new board even though the board is totally intact? Or just the knob?

Edit:

I have now removed the potentiometer and the system works as before without it. the three steel connectors on the bottom of the knob are complete severed and I therefore think replacing the knob should suffice. The knob has the following markings on it:

1B10K 8H2

Anyone know where I can find a replacement for this?

Thanks.

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Bad soldering… But look on ebay or google in Your area for: Alps B10K mono 90 degree potentiometer.

This is a generic part, easy available 10KOhm linear characteristics.

No argument there - I am no electronics guy, which is why I didn’t try the first 10 times I felt like it. :slight_smile: Thank you, I will look for that part.

I notice you didn’t answer the earlier question about whether your unit was second hand…

To say the pot has “become dislodged” is an understatement. Having the PCB pads ripped off like that is not something that happens in normal everyday use. The unit has been abused. Considering there’s a metal bracket too, which presumably secures it to the case, breaking it would take some doing.

Based on what I’ve seen & read here, I’d strongly recommend you get the unit repaired by a professional.

You are incorrect. It has not been abused. It is second hand, but numerous other people have indicated having a similar issue, and it is because this knob protruding out the front is clearly a poor design choice.

In fact, the fact that somehow the software “magically” reroutes its functionality to the headphone mix knob suggests to me that it happens so often that Denon has “silently” integrated a failsafe into the machine to keep it functional even though this happens.

In all likelihood, this happened during shipping - again, because the placement of this knob is very poor.

Finally, if you read the previous few posts, you would see that the repair involves soldering - I may get it done by a professional, but this is because I am no electrician. To suggest the entire machine needs to be looked at it silly.

That much is obvious! FYI I have worked for decades as an electronics repair technician, so I have plenty of experience.

If you want to believe that damage of this extent is not abuse, then so be it, but as the saying goes - “a picture is worth 1000 words”.

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Too me also this looks like the knob was pushed in to the controller, that caused the solder joints to start failing. Bumped during transport or something…

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I think it’s pushed in hard too. In the photo There’s even a substantial opposed right angle bracket holding that knob structure in place. It would be some significant force to dislodge the knob inwards.

Agreed. Assuming it was bumped through transport, its very possible it wasn’t just one bump. Perhaps repeated rattling where that was pressed against a non-cushioned part and eventually one joint after another started wearing down. One singular bump would be really hard to do that in IMO. I mean all three connectors on the potentiometer are completely severed.

I’m looking for the exact piece but I keep getting ones that are slightly different, or with bigger knobs etc.

The thing to do is get it back to Denon. They will have the correct part. They will also be able to either repair the pads and tracks around that area, or replace that PCB.

Dude, please read the rest of the thread, in detail. I’ve already said Denon has ignored my requests, does not provide any help in any way, and there are no repair people around me at all.

I can read, dude. The thing is a mess. You’re not a qualified electronics engineer.

If you want it repaired properly, with the correct parts, it needs to go back to Denon (or at least a Denon authorised repair centre). Try to DIY and you’ll likely just make it worse.

There is another way. Any tv/radio service that can solder. Take the board, take the part, ask for soldering only and done for 10 bucks.

Yep - I have a friend who is an electronics engineer who will solder it for me. Thanks for the help brother. I just need to find the right part now.