good morning, I recently purchased a 1997 naim nap 250 which must have had the power supply capacitors replaced. The problem is that the fixing of the two must have been lost or broken and red silicone was put in to block them. I ask the experts on the subject, what material was the capacitor block originally made of, which I highlighted in the photo and how it was fixed to the chassis. The desire would be to remove the silicone and put something similar to the original or a metal collar as seen in the chrome bumper series. The power amplifier works well and does not hum.
Best to get your dealer to send it back to Naim HQ, although Naim might be inclined to reject it, as there have been unauthorised modifications. I hope not, for your sake.
The best person to answer is probably @NeilS from Naim. Itâs not clear from the photo where this red silicone is; the picture looks pretty normal to me. Neil should also be able to tell you if they are the correct capacitors.
in fact the attached photo (not original) is just to make clear the missing link!! the object in question is the one highlighted circled in red. It is the retainer of the capacitors. As soon as I can, I place the original. I was interested in understanding if the material is plastic or metallic and how it was fixed to the base of the internal chassis. Thatâs all
If you can show a picture of your own 250, Neil will be able to say if they are the correct capacitors, as well as providing fixing advice. It may be that the amplifier has to return to the factory.
Probably best to have the amp checked over and then anything wrong rectified by your dealer or distributor.
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The capacitor retainer is secured with two screws and nuts. If the replacement capacitors are not the same physical size as the originals, that would explain why the original retainer hasnât been used.
I wouldnât be too concerned if those capacitors arenât the same type as the originals, they are probably no longer available. If the silicone is holding the capacitors securely in place, itâs doing the same job as the original retainer, so will be OK.
However. The seller should advise if the unit has been serviced by a non naim authorised company, as that will lower its value.
There should be a four figure number on the capacitors indicating date of manufacture, IE 1712, indicating week 17 2012. Depending on age, the capacitors may need replacing anyway.
I would be concerned if a number of other components where not the same type as originally supplied by Naim. If wholesale changes have been made, it wonât be worth a lot.
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Yes, the latch is gone, the capacitors are firm and stable. I also notice a ferrite at the output of the IEC socket located on the yellow-green ground connector. I donât think itâs original and it has any benefits on the sound. For the rest everything seems ok and original. I attach a general photo. From what has been said it seems that the capacitors have been replaced with others from 2014. They do not appear to be of poor quality - I await your comments.
The code on the capacitors 9614 indicates they where manufactured in week 14 1996.
The blue, red and orange tantalum capacitors would indicate they are very old, probably original from 97.
Note. The date code is the opposite from what I posted the other day, but 96 must be the year, because it canât be the week number, as itâs greater than 52.
Iâd say it needs a service.
The red silicone looks a mess, but itâs doing the job.
Agreed. And ASAP.
The Seller should (IMO) have made it clear that this 250 had been serviced by a non Naim approved person or organization. Such âservicingâ should have been reflected in its price.
YMMV, etc.
I donât think its ever been serviced. The capacitor date code indicates 1996 manufacture, the 250 was manufactured in 1997.
the serial number is in fact 131852 dating back to 1997. In fact the work is quite bad, but do you think removing the silicone and rebuilding a capacitor block is difficult? In my initial question I asked if the retainer was made of metal or plastic. I have the Hicap same series and I could copy it from there. If it were aluminum it would be easy to make.obviously the purchase price reflects the conditions in which it is found. After all these years there are accidents along the way. Letâs try to fix it. Iâm currently using a 1980 Nap 110, one of the very first I think. It sounds satisfactory to my ears.
That definitely looks like someone has âbodgedâ the securing of the capacitors. I wonder why? IIRC the U bracket is black metal (aluminium?). I repeat, it would be best to have the amp checked over and then anything wrong rectified by your dealer or distributor. Anything beyond that likely falls outside of forum AUP here (Electronic DIY discussion). Thread closed.
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