Stressful moments - had to open NAC52 - please reassurance

Hi Guys

Had a real moment this evening.
Began re-stacking the fraim today for arrival of second supercap tomorrow. When I had my 52 in my hands I suddenly recognised a clattering sound within :frowning:
I am not good in those self-made efforts with my holy stuff but I opened it the following way:

  • carfully unscewed the one hexagon socket screw - NAC52 on the side
  • carefully unscrewed the 4 rubber feet - NAC52 on the side but really careful that the tray will not drop down
  • White linen on the table
  • NAC on the table
  • Carefully extracted the tray out front

Found the reason fot the clattering. A little loose screw. Found the place, where it is missing.
There is a screw missing at the “double platines” behind the front and another screw has gone loose. No idea how this has happened.
See pictures:


NAC52.3jpg

At the last picture you can see the location (picture from Kuma).

I think both screws must be loose for some time - so I did not put it back and tightend it. Did not trust in my skills - no hands on my stuff :frowning:

Afterwards I:

  • removed the phone Bords (use a prefix)
  • put the tray in very carefully
  • exchanged the rubber feet with new ones I bought from naim
  • tigtened the rubber feet crosswise by hand - at last carefully with a screwdriver (only a bit)
  • put the hexagon screw back in and tightened it (not with brutal force - careful again)

Put all together an recabled.
Works fine so far - has to warm up again. But…
Than I noticed some flickering of the naim audio logo. Only “audio” - lighting of the symbol and “naim” are fine. Not always - only temporarely and getting better, when warming up (?).
Think, this little flickering has already been there before. Can see it better now, as it is in the upper shelf. Too bad that the flickering logo is in the neighborhood of the „screw“…

Now a list of questions - in order to soothe me (please be gentle - I am easily out of line these days - honestly)

  1. Was my little NAC 52 work described obove done correctly - have I done something wrong?
  2. Can I assume, that NAC 52 is fine again (as it was before) - maybe even better with phono boards removed and new rubber feet?
  3. Do any one have any idea how the screws can get loose. NAC 52 had been at naim service 3 years back (check up and POTS update)? Maybe someone (hope it was naim) forgot to tighten the screws. Can not think that they will come loose by itself.
  4. Is there any problem in SQ with the 2 screws not fixed (platines are steady)?
  5. Is there a technical problem with the screws not fixed - can i still use the preamp?
  6. Can the flickering (lights behind the “audio” logo) still be fixed. Is this possible and can be done at the naim service?

“Once seen - never unseen”
As I saw the screws and the dusty inside as well as the flickering logo, I will give it to a service. Thats for sure.
Maybe it is only for my heart - but so it is.

Too bad, when you are so much in love with your gear…

Thanks a 100 time for answering my (hopefully not too silly) questions!

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I’m afraid I cannot answer your question but understand your pain and hopefully someone with more knowledge will come along and advise.

.sjb

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Thank you so much.
Means a lot :slight_smile:
Sound is fine so far. Will improve in warm up phase a lot.

Flickering had stopped - crossing fingers…

Hi Drago,

Sorry to see your NAC52 is falling apart!
When an item is returned to HQ for service, we do our utmost to ensure that everything is as it should be before it is returned to its owner - the leftmost screw in your last picture is obviously impossible to check for tightness due to the proximity of the fascia, but there is no excuse for the loose screw on the right - that PCB would have been removed during the service & should have been double checked by a second technician before it was released for shipping. Please accept my apologies for this oversight. It may have been three years ago, but still should have been checked.
If you have made sure that the two PCB assemblies are pushed tight together, then no problems should occur unless you wish to ship the preamp again.
The flickering issue with the Naim logo is fairly common & can either be a dry/cold solder joint, or a faulty LED (or two) on the light bar itself (there are several across the top & bottom).

Regards
Neil.

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@NeilS
Thank you so much - must be late in UK too now.
It is far from falling apart and Naim herein Germany is doing a wonderful job. As I bought the 52 as used item I very much hope it is maims fault and not any silly person getting hands on.
If it has happened during service … no problem. We are all human beings :slight_smile: the screw behind the fascia is strange - must have been a real forgotten item.
The boards are fine and fixed - even with 2 screws less. The PCB are as tight as shown in the picture - is this fine?
Will not ship it. Can bring it to Naim by myself - Naim service is nearby.

The flickering has stopped - crossing fingers again. Can this be fixed by Naim?

What do you think of my little surgery. Have I done it correctly?

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Yes, currently we can still replace the light bar. And your fix looks good, as long as you have removed the loose screws so as they don’t short anything out!

As for shipping - you would need to discuss that with Tech Support.
For the time being - I’d say you were quite safe to continue using it.

As you say - quite late in the UK - I’m going to bed now!

Regards
Neil.

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Have a fine sleep and thanks so much again

I removed the loose screw - the other one is stuck and could not harm anything else.
Can I transfer it to Naim in my own car with a lot of pillows underneath - as I do all the time when going to Naim. Packed in original Naim outer package. The boards are really tight and do not move - checked it.

Is there any effect on sound quality due to one stuck screw and flickering lights?
The boards are tight - there must be several more points where they are fixed.

I’m you will be fine to take it in you car. I feel for you. I had kinda remember the same thing happened to a Nac 82 I had a few years ago. Was an easy fix and I could see and get to its hole.

Thanks - will be fine. Also think so.
The lost screw is safe as seems to be stuck has no contact with anything vital laying on the plastic grousing of the Button.
Now it works fine.
Next time it will be moved is for service at Naim.

You had the same - flickering or loose screws?

Hate the bad feeling that I have worsened something. As a matter of fact I have improved it with boards out and new feet :slight_smile:

:+1: Brilliant naim customer service at 2.24am !

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This is more than brilliant and that is why I we’ll never ever mate with another brand.
Naim could do seminars in „how to make customer service and life cycle Management perfectly“
Thanks again to @NeilS - you saved my weekend. This means so much.

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I would have guessed Neil is in another time zone drinking Pina Colada :sunrise:

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