NAP 250 - Click... phut

Hi-Fi Corner
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I blame Rush… Retrospective II was the CD I was trying to listen to.

I do not leave my 250 powered - but I do leave my HiCaps & XPS ‘on’. So I switched my 250 on, in the usual way today. The usual (for my CB era 250) power on ‘click’ happened - but was followed a second or so later by a power dowm ‘phut’…

Huh…? The Fuse…? That’s not happened (to me & my 250) for years… maybe decades…
Ah… Lets try. Fits new spare fuse. Click… Rush now playing.

Why Naim Owners Should Keep Some Spare Fuses… :slightly_smiling_face:

Power Cycles Will Eventually Kill Fuses.

I still blame Rush…

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Fuses do seem to get fatigued especially in things like big amps and power supplies. I used to leave everything on including 250 DR because of this. Plus some of the switches have also failed occasionally.

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Yup. Agreed. I have had this happen with my 250 & my XPS.

The XPS has - generally - got ‘previous’ for doing this, so mine stays ‘on’, to minimize this.

I checked my stock - I still have 2 NAP250 fuses - and 3 XPS ones… :smiley:

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Yes XPS is terrible for blowing fuses, really is quite ridiculous at times, having to vacuum up tiny bits of fuse out of the back of the fuse holder wasn’t fun :man_facepalming:

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:astonished:

At least my 250 fuse failed gently. Didn’t even look blown - but it was. No blacking or broken glass.

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Hi Ian I’ve recently acquired my son’s 250-2 and your post makes me think of keeping a spare, question is tho what’s the fuse spec ?

Thanks Richard

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I don’t know. Mine came from my Naim dealer, free of charge.

They need to be of the correct type and rating.

Your dealer or another Naim dealer, should be able to tell you what you need, for which unit. Not the same for a 250 and an XPS.

@Richard.Dane will know more.

If you want to buy on line, check TomTom.

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PS. Check your 250.2’s mains inlet. There could be a spare fuse within it.

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The FAQ tells all…

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Thanks, Richard.

I neglected to check the FAQ’s… :slightly_frowning_face:

Apologies.

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My XPS fuse shattered into several pieces. Has to use tweezers to remove all the bits. Now just turn it off when away for several days

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How do you change the fuse, which screws should you loosen?:thinking:

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None, just need to get to the back, then the fuse comes out in a similar manner to that of a 13amp plug fuse, ie just lever out the plastic tab carefully. Also if you have had the device from new, then you will find a spare fuse sitting in a dummy holder behind the main fuse.

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IME, you may need a very sharp finger nail to prise open the carrier or a small bladed screwdriver (gently does it). Unless you have clear access to the rear of the kit, you’ll also need to de-stack it, especially if the fuse has shattered…and make sure the carrier is pushed fully back home.

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For owners of much older Naim items, the fuse holder is a separate thing (near to, but separate from the IEC inlet - above the 240V label here) and needs to be unscrewed. Again, only this needs to be addressed.

110

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Me too - newbee !

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Update. Its just blown its replacement fuse. Something is not right here. Further investigations are on going… :thinking:

My replacement fuses are stock from a my Naim dealer from many years ago.

Fuse details -

  • RS Brand on glass
  • Markings on end cap - 250V T4 AL

My 250 is from 1985 and there is nothing on its rear panelt to indicate what the Fuse Rating should be (yes, I checkled). Its Instructions say 4 Amp Anti Surge for 240V.

Just unlucky and/or aged fuses…?

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This question - whats the correct fuse for a CB/Olive 250 - has now been sent into the Naim for comment.

Seems the replacement fuses that I have - marked ‘RS T4AL’ - are likely not correct… :thinking:

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IMG_1592
IMG_15923024×4032 3.27 MB

Fuse rating for olive 250

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21

1985 will be an H & F transformer, which will be 4A.
Try fuses from the Littelfuse 213 range.
It sounds like an inrush issue as a fault will blow the fuse all the time.

Regards
Neil.

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