Brownout damaged components!


Legenda in Aeternum
I couldn't imagine this happening. Friday was very hot, and our power company decreased the voltage in a "rolling brownout." I took a lot of damage to my appliances. But what totally amazed me is that my video card is now not working, and I am only slightly less amazed that the logic board on my garage-door opener needed to be replaced.

Why is low-voltage equipment not designed to survive an under-voltage? I can understand being fried by a lightning strike, but a ten percent drop in voltage? Can anyone explain to me why electronics aren't built to survive this?

To make matters worse, the computer whose video card failed was on a UPS. I test the UPS monthly. The UPS was alive on Saturday, but has failed since then. Not just a dead battery - it can't pass power through and I had to plug everything into a simple surge preventer.

The good news is that the power company may pay for all the damage. But why on Earth should lower voltage break things? It's like (but, I know, the opposite of) when the Enterprise is hit by enemy fire and sparks shoot out of the console and knock extras unconscious. Haven't they heard of circuit breakers / fuses?

(oh, fooey. My custom smileys are gone. I had one of hitting the computer with a mallet. Imagine it here.)


Ouch. That totally sucks.

It might be because your capacitors on your video card were trying to provide enough juice to the card itself all while still not getting enough juice themselves to fully power it, possibly causing melted traces on the video card.

I was lucky myself - I was planning on not buying a UPS for my new computer about 3 months ago, but I just decided to get one anyways. After about 2 months I had my first brown out - luckily my UPS kicked in and saved my computer and tv.

If the power company doesn't pay for your damages, you might want to look into your UPS company asking them about it. They usually guarantee up to a certain amount of dollars for your equipment (i think the last time I saw one was around up to $10,000). Seeing how your UPS failed to protect your computer properly.

By the way what UPS did you have? Also what video card of yours died? Just curious.

Just here to post my regards!


Sep 25, 2011
does the ups provide you power conditioning or is it just a standard battery backup? I work with mobile networking for and undisclosed company ((yea i know)) and they had to switch our stuff because if the UPS are just battery back ups they will output the correct power till the battery is dead then itll just give what it can i.e. the under voltage. However if you have the conditioning ups itll only allow the correct current and voltage and amps through or none at all then default to Batter


Legenda in Aeternum

Standard battery backup. I can't afford a true line interactive (is that the term?). But it comes with software that should shut down my system before the battery runs out. I actually tested it once, unplugging the UPS, and got a clean shutdown. Kind of neat.


Legenda in Aeternum
Any suggestions on a reliable home UPS? I want enough power to run my PC (500 W power supply, running about 400), my main monitor, and the cable modem. Replaceable batteries and UPS communication / software to shutdown or hibernate systems cleanly a must.


I use APC, but they tend to cost more then the competition and lets face it, you still have to replace the batteries after a number of years.

If you want nicer power, a UPS with sineware and not step/modified/ect.

A computer should be able to run and shut down of the lesser ups without issue, but do not try to run them extended on a non sine wave ups.

Newer power supplies seem to make lots of noise when running on non sine wave(kind of worries me, but has caused no damage so far).

Toms did an article with, but it is 2 years old. still relevant.,2785.html

In the end for the price they recommend a modified wave ups. Even with its lower run time, is all you need to save and shut down. I think CyberPower makes many sine wave units now as well.

It is always good to oversize the UPS for the job a bit(or lots if you need runtime). This will lessen the load on the system and let it run longer.

Another option may be to use cheaper ups backups on things like speakers and printers so they do not suck power from your main ups. I had a NOMA brand one for my speakers screen and network and phone because they do not get any benefit from auto shut down and seemed to work ok for those items as a side note this NOMA ups has a HUGE battery and runs forever(My APC needs a new battery, but never had this kind of run time).


Wow, the UPS should have stopped it,

than PSU should have too and some mobos have some protection too.

Was there a spike after the lower voltage? That could have done it.

Its weird. Sorry to hear that.


Legenda in Aeternum

That does seem to be the prevailing theory. Nobody but my airconditioner guy believes that a brownout would damage so much equipment. I just finished fixing my network. The downstairs Ethernet switch now has three failed ports - the ones that were live at the time. The rest are fine. That suggests a spike / induction in the cables to me.

Eh. Once in 20 years isn't that bad. Maybe I'll look for a cheap recording voltmeter - except that it would fry, too, if this happened.


Jul 15, 2008
Why is everybody expecting the UPS to protect from a brownout? Before complaining on the UPS you need to read its specifications at what voltage it will consider as a power loss and cut in from battery power. If your UPS had built in voltage regulation, meaning it monitors outlet voltage at all times and cuts outlet power if it drops or goes above an X amount from 120V. The manufacturer could have said that unless outlet power voltage becomes zero, the UPS has to ignore it and continue supplying wall power. It depends on the specific UPS.

Secondly, were any of your components under load during this? I am thinking the damage may occur because a power supply might attempt to consume a lot more current under a lower voltage (which would kill efficiency), and that can fry a lot of transistors or capacitors. I am not sure on this however.

There is user who is called InvalidError...he may very well know why. I'd message him.