[conspire] Computer Gremlins -- bad AC power?

[Dana Goyette]

A couple of extra notes:
* The PSU that was paired with the dead server board is now
successfully driving another board, but no GPU in that machine.
* It's possible the dead board was already on its way out, because I
bought it secondhand from eBay, and it had some oddities with powering
one of the PCIe slots.
* I've read things about LG monitors failing due to a corrupted
EEPROM, so it may be a coincidence, or it may have gotten all its
damage before I put it on the big UPS.
* The big UPS's "green mode" bypasses AVR components for efficiency,
and warns that may take a couple of milliseconds to react to voltage
fluctuations.  I've now turned off that feature.
* The small UPS running the cable modem used to be at my parents'
place, but I gave them my previous big UPS last year when a vacuum
cleaner in a neighboring room kept making their UPS drop load, taking
down the network and my mom's Mac.
* My dad used a cheap off-brand battery in the small UPS when he last
replaced it, and it handles a laptop power supply (HP T730 thin client
with OpenWRT) and a wifi access point, but shuts off instantly if a
desktop PSU is connected, even if the PC isn't running.

My dad has some electrician knowledge (he's done a bunch of wiring),
but for the dimming lights problem, he ended up having to just search
the internet like anyone would, since he doesn't have formal training
or certification.  What would it likely cost to have somebody take a
look at it?  Is it a thing we can get the power company (PG&E) to
check out for free?

On Thu, Sep 30, 2021 at 11:42 PM Rick Moen <rick at linuxmafia.com> wrote:
>
> Quoting Dana Goyette (danagoyette at gmail.com):
>
> > Ever since I moved down to San LUIS OBISPO, I've had way more weird
> > crashes and hardware failures than I've ever had before.  Can anyone
> > suggest what might be the cause?  Is our power circuitry messed up in
> > some way?
>
> I had a great theory, and then:
>
> > The small UPS running our cable modem and router shows the input
> > voltage randomly drifting between 121 and 125 volts.
>
> Well, shucky darn.  The damage plus the phenomenon of lights dimming and
> brightening could have been something like what happened at our house,
> some years ago, when the main house feed's neutral lead broke at the
> roofline.  Voltage started swinging.  We called in an electrician, who
> isolated the problem to the main house feed, and we then called PG&E,
> which ran a new line from the pole.
>
> In your case, I'm not sure, but I'd absolutely call in an electrician
> and have some root-cause diagnosis done.  This sounds to me like a
> classic case of "bring in the professional help".
>
> You might want to get a voltage regulator box to put between your
> computer gear and house power, just as additional isolation.  I do this,
> and would try to never _not_ do so, in the future.  (Laptops don't need
> that, IMO, having plenty of isolation.)
>
> I have in my toolbox an AC receptacle tester that purports to be able to
> report various sorts of wiring errors/faults in the AC feed, somewhat
> like this one:  https://www.ebay.com/itm/233868157505
>
> However, your place's problem sounds serious enougn I'd call in the
> pros.
>
>
> _______________________________________________
> conspire mailing list
> conspire at linuxmafia.com
> http://linuxmafia.com/mailman/listinfo/conspire