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PSU clicks when powered up (twice!)

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PSU clicks when powered up (twice!)

Postby hooty2 » Thu May 06, 2021 7:24 pm

Hi,
I have a APC Back-UPS 400Va for my sound room (from September 2014).

after 'work', I leave the APC plugged in at the mains, but press 'OFF' the little green light on top of the APC.

For a few months, the APC has started screaming at me when I turned stuff on...especially the main PC....
So...i turn the APC little green light on, and wait, (maybe 10/15 secs) until it clicks...then i turn PC on, then I wait again until it clicks again and I can then turn the monitors on.
If I don't do this the APC noisily (continuous tone) objects.

Also (related?)...in another thread about my battery inside the PC discharging and messing up BIOS settings (resolved)...Hugh said this:
"But for what it's worth, I never turn my PC off at the PSU switch, only ever a software shutdown (unless I'm changing hardware). Been doing that for over 15 years now with at least seven different computers and without any problems at all."

does that mean I can leave my APC plugged in to mains with mains switch on..and...also leave the little green light on?
(nb: I write children's stories:))

question: is the clicking APC telling me something?
thanks in advance
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Re: PSU clicks when powered up (twice!)

Postby Hugh Robjohns » Fri May 07, 2021 9:30 am

hooty2 wrote:question: is the clicking APC telling me something?

Yes, of course it is! Check out the 'Status indicators' of the manual

For a few months, the APC has started screaming at me when I turned stuff on...

A constant tone indicates either a faulty battery or an overload condition. The flashing lights will confirm the situation.

So it could be that your computer and monitors are drawing more power than the UPS is designed to provide, or that the battery inside has reached the end of its working life and needs replacement. Or it could possibly be that you aren't leaving the unit on long enough to fully charge the battery (they recommend at least 16 hours).

...does that mean I can leave my APC plugged in to mains with mains switch on..and...also leave the little green light on?

You could, and I do. I have two Smart 1500 UPSs and they never get turned off. The PCs are only shutdown through software, never the mains switch at the back of the box, and the monitor screens shut themselves down when their digital video signals disappear.

However, leaving the UPS on just to avoid it's warning tones is obviously counterproductive because when you get a mains power interruption your UPS won't be able to do anything if its battery is dead!

So, figure out exactly what the beeping and clicking is all about, and fix it! And I'd do it as a matter of urgency since these things fail when they can cause the most havoc! ;)
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Hugh Robjohns
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Re: PSU clicks when powered up (twice!)

Postby hooty2 » Fri May 07, 2021 9:58 am

ON IT :thumbup:

My late gran used to say (totally unfazed, yet resigned).."oh well, if it's not one thing it's another"
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