XPSDR won't power up

Hi everyone.

I have had my system switched off whilst I rearranged the connections between the 300 DR and its power supply.

Now that I have come to switch it all back on again, the Supercap which powers the ndx2 won’t fire up. No lights. Nothing.

Bearing in mind that I haven’t actually touched the Supercap, I’m a bit baffled.

Can anyone point me in the right direction please?

I’d start with checking the fuse in the XPS. You should find a spare in the fuse carrier.


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And make sure the power cabling is well-seated as, if not, this can cause fuses to blow.


Thanks for the suggestion.
I’ve already substituted the power cable.
Are you referring to an internal fuse in the casing?


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Right by the IEC socket, there’s a tab. Pull out carefully – there could be broken fuse glass in there. There should be a spare fuse lurking in the inner holder. Switch over.

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Ok, now I feel really stupid.
It’s the XPSDR that isn’t powering up (not the Supercap)

Let’s start again.

Same question, but about the XPSDR.

I have amended the title

Switch off (assuming the front switch isn’t ‘sticky’?).

Same answer re the replacement fuse aspect. XPS’s can have issues it seems.

If it isn’t the fuse, then check your consumer unit board, as the current draw may have tripped a breaker.

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The switch on the front panel feels ok. It seems to click on latch as it did before.

The system has its own dedicated power supply, so if that had tripped, none of the other boxes would work.

I’ll try and find the fuse on the XPSDR now.

Thank you.

As simple as that!

You could tell how flustered I was by the fact that I’d forgotten what the boxes were called! Haha!

I hate dealing with things like this. You always expect the worst.

Thanks everyone for your quick responses and lack of mocking.


XPSs can sometimes eat fuses due to the initial current draw. See the below – if you haven’t got some spares, I’d get some from your local dealer, making sure they’re the right type.

Equipment Fuses - Frequently Asked Questions - Naim Audio - Community


I’ll be at the dealers sometime this week anyway, so I’ll grab a few.

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Agreed. Get some spare fuses of the correct rating, via your Naim dealer…

Ah yes, wot we in the trade call “unscheduled rapid disassembly resulting from excess V/I”

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& “slow blow” types.