What just happened?! 555 PSDR

I tried connecting my 555 PSDR to my NDX2. I thought I had disconnected it but I must not have. I plugged the mains back into the NDX2, heard a pop and smelled some smoke. I then tried to connect the 555PS DR back to my ND555 and now no power goes to the ND555. Did I fry the 555PS?! I’m so frustrated. Completely my fault and done in haste but dang it!

Or perhaps shorted out the Burndy? @Richard.Dane any advice? Thanks!

You’ve probably blown the fuse in the 555. Does the logo light up when it’s on? If not, check the fuse. You should find a spare inside the little holder.

The 555 has huge caps and you should wait a minute or so after turning off before disconnecting it from the NDX2.

You mention plugging in the NDX2: it should not be connected to the mains if powered by an external PS.

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The 555ps lights up. I had it disconnected from the mains when i fist had it connected to the NDX2 but don’t know why it wasn’t playing any music through the system? I thought I disconnected the Burndy but must have forgot and then plugged the NDX2 in. I did shut down the 555PS but it must not have completely powered down. Ugh

Any you didn’t turn off the wrong power supply when doing the change? Many boxes, many cables.

No, for sure it was the 555 PS.

A bit confused as to exactly what you did but it sounds like you plugged a powered 555PS into the NDX2 (not sure if the NDX2 was still connected to the mains at the time…).

If the logo still lights up on the 555PS, then the fuse is fine, but it sounds like you may have taken out something internally on the 555PS, given the pop and smell. I would be wary of connecting this up to another piece of kit for now, so i would get the 555PS and Burndy cable to your dealer and get it checked out.

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Yeah, I think it was internal as well. No dealers close by that could look at it though I’m afraid.

NDX2 works still so that’s good. Just don’t have a way to run the ND555 now. :frowning:

First world problems. Thanks for the help everyone.

Word to the wise, don’t try and multi task hifi events with an 8 and 6 year old in the house! I knew better but thought things were in a good place with them.

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A pop and a burning smell suggests trouble. Not sure if this can be sorted without a return to Naim.

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Not sure here but the pop and burning smell indicates probable trouble. I guess it’s a mistake you’ll hopefully only ever make once.

Perhaps @NeilS can speculate on what has happened here…

I haave another Burndy I could try, should I do that?

I’d get the 555PS looked at. Given your luck earlier in the day, i wouldn’t tempt fate with the PSU in an unknown internal state.

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I know the feeling. I once shorted out the speaker cables of my then Linn active system whilst trying to do some rearranging. (I should say Aktiv! )
The result was that one of the LK140 power amps was fried! Similar smell I suspect. Like others have said, I’d refrain from plugging it back in and get it checked. Hopefully it can be sorted without too much stress. The LK 140 was soon repaired and went on to perform perfectly for over 20 years.

were you using the correct burndys at the time? the one for an ndx2 would be different to say an nds/nd555

also it wouldnt make any difference if the ndx 2 had a power cable going to it because the link plug would be removed

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The NDX2 has protection against being simultaneously powered by the Burndy & mains, resulting in a warning message on screen and no damage should occur if using the correct XPS Burndy.
If a 555 Burndy (only) is used, the NDX2 just won’t work.
A 555 Burndy & mains - now that might cause damage.
I’d guess it may damage the protection resistors on the DR module(s) in the 555PS.


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Wow, thank you everyone! Another example of my ignorance played out beautifully. I used the Burndy from the ND555 which is why it wasn’t working correctly. It powered the NDX2 on but no signal. I then must have hastily plugged in the NDX2’s mains while the Burndy was connected and the 555 PS wasn’t completely powered down. Hence, the pop and smell of smoke. I’ll be contacting Focal/Naim North America and hopefully it can be serviced.

Wishing you all a great weekend!

Thanks again!

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glad you got to the bottom of it mate, had a feeling it was burndy related especially as you have both s-xps and 555 burndys


This might be one of the reason why Naim want to standardise all power supply now.