I’ve just unplugged my boxes to photograph the serial numbers for insurance and upon plugging them back in again (not a full break down and build up) the XPS isn’t powering on.

I’ve checked the power cable, socket and XPS fuse and all is good.

Any ideas? Is this a return to Naim situation?


Stupid question, but are sure the fuse is good? Xpsdr does like to eat them randomly. Have you tried the spare?

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Double check the inlet fuse in the back of the IEC socket. There should be a spare in there.


Alas no spare is present so imagine this must have happened to the previous owner too. The fuse looks ok, however I expect it has blown given the comment above.

Assume it’s a standard fuse so no requirement for anything exotic? Just a trip to B&Q for an “essential” purchase tomorrow?

Actually will the other boxes such as the HiCap have a compatible spare? Could be a quick fix this evening…

No, it’s a very specific fuse you need. A Naim dealer can supply. It’s a T fuse and rating and type, even the make is really critical. Get a bunch of them, just in case. Only ever use the exact rating and type of fuse - it’s critical for safe operation.

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Thanks Richard will do!

Have you used a multimeter to confirm the fuse is open circuit, or do you believe its blown/ it looks blown?

Xpsdr normally use a 20mm T2.5Amp slow blow fuse. Your dealer should be able to supply one.

Also read the FAQ, even the direction seems to matter:

I’ve seen several references to the XPS being prone to blowing the protection fuse and indeed, when I first acquired mine it went through a couple which was disconcerting at the time.

Is the XPS in particular prone to doing this and if so why, or is the reporting thereof coincidental?

Not so much the XPS, but the XPS2 can be more prone than usual. I guess it was down to the particular transformer and regulations. Upping the fuse rating meant it wouldn’t pass regs and a value in between didn’t really exist, so it had to be a 2.5A T fuse which meant it was right on the edge at switch-on when you have the greatest in-rush of current.

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Interesting. Thanks

Probably not the cause but make sure the plug is fully inserted.
Powerlines can be tough to plug in

If the XPS2 left powered up, the Fuse lasts a long time… :slightly_smiling_face:

Why does hifi kit like amps etc have a fuse next to the mains inlet and do not just rely on the fuse in the plug top?

Also why do my DVD player, wide screen TV, Sky box and AV amp not have a fuse next to the mains inlet but just rely on the fuse in the plug top?

Just asking out of curiosity🤔

partly because lots of people plug things in with 13a fuses, which is far too much current for many devices - the only way to ensure the right rating is to either permanently attach the power lead with an integrated plug at the end, or to have internal fusing. It’s to protect the less aware from themselves…

Sorted! Thanks for your help everyone. It was indeed a blown fuse.

Thankfully my dealer was popping by this morning with a Mu-So to play with and a couple of phono amps, so I managed to get in touch and he bought a few spares.

Need to get everything up and running again, but for now wow… the Mu-So really is an impressive box even compared to the Qb!

Thanks again

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Good that it is fixed. Out of curiosity did he leave you a spare to pop inside the IEC socket?

And most importantly, did he fit a 2.5A or 3.15A fuse? Both will be slow blow rated.

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He left me two spares - what a guy!

They are rated T-2.5A

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OK. That’s good.
I know my dealer has long since run out of T2.5A fuses. Fits T3.15A now. Says he has never seen an xpsdr back after fitting the T3.15A fuse.

Well of course he won’t see an XPS back after this, because the fuse has lost its purpose. Question is if there is any electrical issue in the XPS and the apartment burns down, does he pay for the damage? Because your insurance will not.