UPS blew out power supply - how?

A few weeks ago my UPS blew out the power supply to my main computer monitor - an old Apple 30" Cinema Display - forcing me to buy a new one (I couldn't wait for a replacement one to arrive).

Thankfully that UPS didn't blow out either of the computers connected to it, but it doesn't put out voltage now. I'm 100% sure the its batteries are bad, because it's very old too.

My question is what can go wrong with a UPS to cause this? I can replace its batteries if that's all it takes, but I have a thing about not liking my equipment to be destroyed by a device intended to protect it.

TIA

As an aside, the monitor I replaced it with - the 32" 4K Samsung that Best Buy had in stock, limiting my choice to this one or this one - is very good.

On 3/5/2021 3:29 PM, nickbatz wrote:
> A few weeks ago my UPS blew out the power supply to my main computer monitor - an old Apple 30" Cinema Display - forcing me to buy a new one (I couldn't wait for a replacement one to arrive).

Well, if it "blew up" something, there was likely a transient involved.
Was the UPS running on batteries at the time, or trying to but couldn't
because the batteries were dead? A lightning storm? A terrorist?


--
For a good time, call http://mikeriversaudio.wordpress.com

Hey Mike, hope you're staying safe.

We had terrorists in my garage a couple of years ago. They were incredibly prolific, pooping everywhere. I and three other big guys spent a very long day taking out 25 years of accumulated stuff, cleaning it, and throwing away 2/3 of it. A pest control man got rid of the terrorists, and then sealed every opening in our house so they couldn't get in again (plus we replaced the garage door so it closed tightly).

As to lightning storms, the weather is always perfect in sunny Southern California.

But your theory makes sense, because we do have voltage fluctuations from time to time. I have no idea whether the UPS was running on batteries then.

And I still don't know whether replacing the batteries and trying to keep the UPS going is a good idea.

I do have two multi-outlet isolation transformer boxes, which are a different thing, but they should offer some protection.

On 3/5/2021 3:50 PM, nickbatz wrote:
> As to lightning storms, the weather is always perfect in sunny Southern California.

Well, I've heard of a few power problems out there, but I still wish I
had bought a house in sunny southern California when I was hot on that
trail. I've got my shots, but it's still too much trouble to go anywhere
further than to the grocery store

> But your theory makes sense, because we do have voltage fluctuations from time to time. I have no idea whether the UPS was running on batteries then.
>
> And I still don't know whether replacing the batteries and trying to keep the UPS going is a good idea.

With the last two UPSs (well, to be fair, they were both the same make
and model) that needed new batteries, I found that I could replace the
whole UPS for about $10 more than just replacing the batteries, and that
got me better filtering and faster swtichover, and maybe even a better
battery with the newer units. So that's what I did. Us old geezers have
a hard time accepting that they don't make things that last forever any
more.

A UPS is a good idea, particularly if there's writing to memory in real
time involved - including disk drives and virtual (diskless) disk
drives. More than once I've had power go out when I was recording and
the power went out. The take in progress was lost since I didn't have
the mic preamps running from the UPS, but the computer, or in this case,
the hard disk recorder, was able to shut down orderly.

> I do have two multi-outlet isolation transformer boxes, which are a different thing, but they should offer some protection.

Generally those offer surge protection and some are voltage regulators,
but when the power coming in goes off, so does the power going out.



--
For a good time, call http://mikeriversaudio.wordpress.com

nick is batz wrote:
>
> A few weeks ago my UPS blew out the power supply to my main computer monitor -

** Bull****.

> Thankfully that UPS didn't blow out either of the computers connected to it,

** Proving you are posting bull****.

>but it doesn't put out voltage now. I'm 100% sure the its batteries are bad, because it's very old too.

** ROTFL !!

> My question is what can go wrong with a UPS to cause this?

** The stupid owner.

Vlad, is that you?

nickbatz > wrote:
>A few weeks ago my UPS blew out the power supply to my main computer monitor - an old Apple 30" Cinema Display - forcing me to buy a new one (I couldn't wait for a replacement one to arrive).

Maybe. More likely the power supply on the monitor failed and took out the
UPS. To know for sure you'd have to know what failed on each.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Friday, March 5, 2021 at 3:42:49 PM UTC-8, Scott Dorsey wrote:
> nickbatz > wrote:
> >A few weeks ago my UPS blew out the power supply to my main computer monitor - an old Apple 30" Cinema Display - forcing me to buy a new one (I couldn't wait for a replacement one to arrive).
> Maybe. More likely the power supply on the monitor failed and took out the
> UPS. To know for sure you'd have to know what failed on each.

Hah. I hadn't thought about that, but then I don't normally stand on my head.

In any case, I have a new power supply for the monitor (that I have to wire - the OEM one uses a proprietary plug with lots of tiny parallel wires instead of the two normal ones). Hopefully that's all that's gone.

But I don't know how to check the UPS beyond obvious things that you can see are damaged, nor do I have the inclination to waste a lot of time on it - for the reason Mike says: new batteries aren't a lot cheaper.

nickbatz > wrote:
>On Friday, March 5, 2021 at 3:42:49 PM UTC-8, Scott Dorsey wrote:
>> nickbatz > wrote:
>> >A few weeks ago my UPS blew out the power supply to my main computer monitor - an old Apple 30" Cinema Display - forcing me to buy a new one (I couldn't wait for a replacement one to arrive).
>> Maybe. More likely the power supply on the monitor failed and took out the
>> UPS. To know for sure you'd have to know what failed on each.
>
>Hah. I hadn't thought about that, but then I don't normally stand on my head.
>
>In any case, I have a new power supply for the monitor (that I have to wire - the OEM one uses a proprietary plug with lots of tiny parallel wires instead of the two normal ones). Hopefully that's all that's gone.

Any idea what failed on it? Is the fuse open? Does the big power transistor
test shorted? Does it smell like bad capacitor?

>But I don't know how to check the UPS beyond obvious things that you can see are damaged, nor do I have the inclination to waste a lot of time on it - for the reason Mike says: new batteries aren't a lot cheaper.

Start by checking fuses. You may just have a blown fuse somewhere on the
secondary side, caused by the monitor failure.

Is this a cheap standby UPS or an online type? If it's a standby UPS and
you get no output at all, look for bad fuses and make sure the changeover
relay is closing properly when it gets power. If you don't hear a nice
ka-chunk when you apply power and the relay switches over, you may have a
more substantial issue.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."