NAC112 Pre amp - all lights flashing!

Hi-Fi Corner
1

Hi Everyone,

The system played fine for 5 minutes yesterday and then sound stopped and all lights on the pre-amp started flashing. It wouldn’t react to any of the controls so turned off at mains. Turned it on again and it played for 5 mins and the same thing happened - and it keeps happening.

Any ideas?

Thanks

Andy

2

Probably one for @NeilS However, in the meantime, a few questions: What else do you have connected to the NAC112? Are you using a dedicated power supply such as a Flatcap? Or are you powering from the internal supply of a Naim power amp, such as the NAP150?

When it happens does the power amp appear to switch off?

3

Is there a link plug in the back?

4

Hi - It is powered from the Power amplifier. Both the power amp and the phono stage stay on as normal.

Thanks

Andy

5

Hi - not sure what a link plug is - it has all the leads and plugs from when the dealer set it all up.

Thanks

Andy

6

With no link plug you would have nothing from the pre-amp at all. However, you could try powering it all down, removing the link plug and then re-fitting it. Then power up again.

The link plug is located on the farthest left of the NAC112 back panel as shown above.

7

Exactly that, but the OP has not said yet whether he’s using a Flatcap or not.

8

Andy has mentioned that pre-amp is powered by the power amp, so no flatcap.

9

Maybe I should read all previous posts rather than just jumping to the end :grimacing:

10

Sounds a bit crazy!
Can you describe the nature of the flashing - speed & rhythm?
Is there anything else in the room that could be throwing out spurious IR, like screens/monitors, light bulbs etc?

Regards
Neil.

11

Hi - the flashing was very rapid - like 3 a second. But that has changed - it now plays for around 8 minutes and then goes dead. No flashing lights on preamp now but the Naim logo drops to half brightness.

No infra red sources in the room and nothing is in there that hasn’t been there for years - all very odd!

12

I wonder whether something within the pre-amp power supply in the power amp is failing. Is the power amp a NAP150?

13

Ok, that sounds like the main filter capacitor for the preamp power supply within the power amp has failed.

Regards
Neil.

1 Like
14

Some progress! Have narrowed down the problem.

I tried the system with one source at a time plugged in - totally fine with all until the phono stage is plugged in to the preamp.

Regardless of the source, if the phono stage is plugged in, the preamp dies after a few minutes, although oddly, the phono stage light stays lit.

I had it playing here for hours, but not with the phono stage plugged in.
The flashing has stopped - when it dies the preamp logo drops to half brighness for a few seconds and then goes out completely.

So we have at least narrowed it down - I assume its something in the phono stage.
Andy

15

Is the phono stage normally connected to the Aux powered DIN on the 112?

Regards
Neil.

1 Like
16

You’re a lucky chap. Those clever Naim people have diagnosed the problem.

All you have to do now is pay the bill for fixing the amp!

17

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