PC reboots when turning the ceiling fan on/off

[twdorris]

I know it sounds stupid, but I swear it does this. My PC will reboot
sometimes when I walk over and turn off the ceiling fan! I also have a
small radio shack 12v power supply next to me that I use to power some
external boards. The PC will reboot when I turn that power supply on or
off sometimes as well.

If the PC is going to reboot, it will respond instantly to flicking
either of these switches. Of course, it doesn't do this all the time
or else I'd have an easier problem on my hands... First the modem will
hang up (at the exact moment I flick one of those switches), then the
PC will complain about losing the satellite connection and then it just
powers down. It does not indicate that it's shutting down in any way.
It just complains about what it thinks are devices suddenly being
disconnected form it, then blam, it goes blank. Sometimes I will get
the BSOD, but usually nothing. This probably happens 3-4 times a week
with maybe 30-40 opportunities. So, yeah, maybe 10% of the time or so.

Clearly there's a hardware issue somewhere. But where is the most
likely place? I don't mind replacing the motherboard (an older MSI
845G Max-L) or the processor or the power supply or whatever. But I
can't very well justify replacing all that old hardware when doing so
would quickly add up to the cost of a new machine. But if I can zero in
on a likely component or two, with some sound reasoning behind the
direction, I'd be willing to pay a couple hundred to give it a shot.

FWIW, I have tried moving the radio shack power supply to a different
circuit in the house, but the PC will still randomly shutdown like
this. Any and all help would be greatly appreciated.

Thomas Dorris

 

[Lawrence Lucier]

I know it sounds stupid, but I swear it does this. My PC will reboot
sometimes when I walk over and turn off the ceiling fan! I also have a
small radio shack 12v power supply next to me that I use to power some
external boards. The PC will reboot when I turn that power supply on or
off sometimes as well.

Clearly there's a hardware issue somewhere.

And or house wiring issue............

FWIW, I have tried moving the radio shack power supply to a different
circuit in the house, but the PC will still randomly shutdown like
this.

.........but still hooked up to your outboard gear??

You haven't exactly described what your outboard gear consists
of.......are they shielded properly?

Any and all help would be greatly appreciated.

I probably would try unhooking all your outboard gear and seeing if the
computer barfs.........if it does, then:

Physically move the computer, minus your outboard gear, to another part
of the house. Observe it's behaviour as a stand alone unit while
toggling fan or other switches. If it behaves itself, then add your
outboards back one by one,while repeating the switch toggling test. If
after all the outboard stuff is added back, it behaves itself, then it's
probably time to start looking at the house wiring at the computers
original location.

 

[Guest]

My PC will reboot sometimes when I walk over and turn off the ceiling fan!
I also have a small radio shack 12v power supply next to me that I use
to power some external boards. The PC will reboot when I turn that
power supply on or off sometimes as well.

If the PC is going to reboot, it will respond instantly to flicking
either of these switches.

Changing the motherboard will probably do no good. Try plugging
everything into an EMI filter to block the high-frequency surges
generated by motors and by turning devices on and off. Better surge
protectors contain EMI filter (APC, Tripplite, Curtis), but many have
only MOVs, which will do nothing for your problem because they let all
surges below a certain voltage level pass right through. In
comparison, EMI filters work only on frequency (surges tend to be brief
and generate high frequencies) and can block surges down to zero volts.
Radio Shack sells a "hash filter" specifically to block EMI.

You may need an EMI filter on the output side of the 12V supply, and
your external boards may even have empty places for the needed
capacitors and chokes.

Another possibility is that your computer's power supply lacks an EMI
filter, but only the worst ones are built that way. To verify without
opening the supply and looking for empty places on its circuit board,
use an AM radio tuned to a weak station. If reception becomes
noticeably worse when the computer runs and you hear white noise or
buzzing, then there's no EMI filter.

 

[kony]

I know it sounds stupid, but I swear it does this. My PC will reboot
sometimes when I walk over and turn off the ceiling fan! I also have a
small radio shack 12v power supply next to me that I use to power some
external boards. The PC will reboot when I turn that power supply on or
off sometimes as well.

If the PC is going to reboot, it will respond instantly to flicking
either of these switches. Of course, it doesn't do this all the time
or else I'd have an easier problem on my hands... First the modem will
hang up (at the exact moment I flick one of those switches), then the
PC will complain about losing the satellite connection and then it just
powers down. It does not indicate that it's shutting down in any way.
It just complains about what it thinks are devices suddenly being
disconnected form it, then blam, it goes blank. Sometimes I will get
the BSOD, but usually nothing. This probably happens 3-4 times a week
with maybe 30-40 opportunities. So, yeah, maybe 10% of the time or so.

Clearly there's a hardware issue somewhere. But where is the most
likely place? I don't mind replacing the motherboard (an older MSI
845G Max-L) or the processor or the power supply or whatever. But I
can't very well justify replacing all that old hardware when doing so
would quickly add up to the cost of a new machine. But if I can zero in
on a likely component or two, with some sound reasoning behind the
direction, I'd be willing to pay a couple hundred to give it a shot.

FWIW, I have tried moving the radio shack power supply to a different
circuit in the house, but the PC will still randomly shutdown like
this. Any and all help would be greatly appreciated.

Thomas Dorris

You might have poor house wiring but even so, the most
likely suspect is your power supply itself. What make &
model is it?

 

[twdorris]

Thanks, guys. Those are all good points. I will move forward on this
using your suggestions and tips.

Thomas Dorris

 

[twdorris]

Quick update on this. I did install a brand spanking new power supply,
but the problem persists. In fact, I noticed a new twist to it. The
PC rebooted once when all I did was insert a USB/DB9 serial adapter in
one of the front USB ports. I don't normally remove that piece, so I
would not have expected to notice this before.

I also noticed that when the thing does a BSOD, it's always at the same
address, 0x8041E641. Something about an unhandled exception I think.
I will need to do some digging to figure out how to work with the
memory dump file it supposedly spits out during a BSOD. At least it
says it's doing a kernel dump somewhere. Maybe that will be useful,
maybe not. Maybe I'll just put this possessed PC on the shelf and
start fresh.

FWIW, this is a Windows 2000 Service Pack 4 machine.

Thomas Dorris

 

[Robert Heiling]

Quick update on this. I did install a brand spanking new power supply,
but the problem persists. In fact, I noticed a new twist to it. The
PC rebooted once when all I did was insert a USB/DB9 serial adapter in
one of the front USB ports. I don't normally remove that piece, so I
would not have expected to notice this before.

I also noticed that when the thing does a BSOD, it's always at the same
address, 0x8041E641. Something about an unhandled exception I think.
I will need to do some digging to figure out how to work with the
memory dump file it supposedly spits out during a BSOD. At least it
says it's doing a kernel dump somewhere. Maybe that will be useful,
maybe not. Maybe I'll just put this possessed PC on the shelf and
start fresh.

FWIW, this is a Windows 2000 Service Pack 4 machine.

A quick check of the posts didn't show any talk of the possibility of your house
outlets not being grounded. Just for giggles, there is a small inexpensive
lo-tech tester (Radio Shack?) that plugs into any 3-prong 120v outlet and will
diagnose a number of problems and show them via leds. A floating ground can do
wonders!

Bob

 

[twdorris]

Yet another update... I have checked the plugs in this room and they
"appear" fine. Polarity is consistent with the rest of the house and
ground appears good as well. I have also run dumpchk on the minidump
file. That address listed above apears to be in the kernel itself!
Ugh. Not what I wanted to see.

Moving the PC around and trying to do my work from another location
really isn't an option. My satellite connection comes in at this point
and there's lots of equipment I'd have to move in order to effectively
work from another location. Given that the reboot happens even when
all I do is install a new USB device leads me to discount the house
wiring suggestion. Of course, I'm still left wondering how anything
could respond to the ceiling fan activation without there being some
sort of power supply/wiring type issue involved here.

Thomas Dorris

 

[Todd]

Yet another update... I have checked the plugs in this room and they
"appear" fine. Polarity is consistent with the rest of the house and
ground appears good as well. I have also run dumpchk on the minidump
file. That address listed above apears to be in the kernel itself!
Ugh. Not what I wanted to see.

Moving the PC around and trying to do my work from another location
really isn't an option. My satellite connection comes in at this point
and there's lots of equipment I'd have to move in order to effectively
work from another location. Given that the reboot happens even when
all I do is install a new USB device leads me to discount the house
wiring suggestion. Of course, I'm still left wondering how anything
could respond to the ceiling fan activation without there being some
sort of power supply/wiring type issue involved here.

Thomas Dorris

In the original post you said "First the modem will
hang up (at the exact moment I flick one of those switches),"

This could be because of something that your computer is feeding
back to the modem over the network cable, but it sounds to me
more like a power issue at the modem, which means house wiring.

Do you know what is on the same house wiring circuit as the
computer? I assume that the Radio Shack power supply is,
and the modem, but how about the ceiling fan? When you
operate things on other house wiring circuits do you have the
problem? How about when your air conditioning starts?

Do you have aluminum house wiring? If you do have you had
the connections inspected?

Have you used a meter to check the voltage at your wall
jacks? Check it first with everything disconnected or turned
off. Then measure it again with everything powered up. Add
more stuff to get it close to the rating for that circuit, 15 or 20
amps.

Can you run a heavy duty extension, preferably 12 gauge or
bigger,to another room and on a different house wiring circuit?

I believe that it is your house wiring. It sounds like you have
a high resistance connection somewhere in the circuit that
feeds the room where your computer is. If you have aluminum
wiring, you probably have high resistance connections through
out your house.

I understand that moving your computer to a different room
permanently is not an option, but you can certainly do it
temporarily for trouble-shooting., and before you can go
on to anything else, you have to prove the house wiring is
good.

On the other hand it could be your power supply. You say
"Given that the reboot happens even when all I do is install
a new USB device leads me to discount the house wiring
suggestion." That could still happen if there is a high
resistance in the circuit that the power supply is plugged into.

Have you upgraded your computer by putting in a new
motherboard or cards that draw a lot of power? How
many Watts is your power supply?

 

[Robert Heiling]

Yet another update... I have checked the plugs in this room and they
"appear" fine. Polarity is consistent with the rest of the house and
ground appears good as well. I have also run dumpchk on the minidump
file. That address listed above apears to be in the kernel itself!
Ugh. Not what I wanted to see.

Moving the PC around and trying to do my work from another location
really isn't an option. My satellite connection comes in at this point
and there's lots of equipment I'd have to move in order to effectively
work from another location. Given that the reboot happens even when
all I do is install a new USB device leads me to discount the house
wiring suggestion. Of course, I'm still left wondering how anything
could respond to the ceiling fan activation without there being some
sort of power supply/wiring type issue involved here.

Satellite?? You might want to look into the grounding, lightening protection,
etc, arrangements of the satellite dish and associated equipment. Even though
the ceiling fan & usb actions aren't guaranteed to cause a reboot, perhaps some
repetitive testing of those with the satellite equipment disconnected from the
computer might point at the problem?

Bob

 

[drifter]

Yet another update... I have checked the plugs in this room and they
"appear" fine. Polarity is consistent with the rest of the house and
ground appears good as well. I have also run dumpchk on the minidump
file. That address listed above apears to be in the kernel itself!
Ugh. Not what I wanted to see.

Moving the PC around and trying to do my work from another location
really isn't an option. My satellite connection comes in at this point
and there's lots of equipment I'd have to move in order to effectively
work from another location. Given that the reboot happens even when
all I do is install a new USB device leads me to discount the house
wiring suggestion. Of course, I'm still left wondering how anything
could respond to the ceiling fan activation without there being some
sort of power supply/wiring type issue involved here.

Thomas Dorris

Have you checked you PSU? If it is on the edge and the supply volts dip
when something else is turned on in the house that may be enough to tip
the PSU off.

 

[devanom]

Hi wizards,

I must how was flabbergasted when I discover this particular issue on the forum.
I exactly have the same problem.

I am using HT Pentium 3.2GHz and 3GB RAM with Windows2000 SP4 OS.


1. When I switch the lights on/off in my room, the PC which is plug to the socket directly below
reboots.
2. When I switch the ceiling fan on/off in my room, the PC reboots.
3.When I plug-in any usb accessories such as external HD to the usb port behind PC,the PC
reboots.I get a BSOD memory dump starts to take place.

This did not happen in the past but I don't know.Could be because recently I plugged in an usb
wifi adapter at the front usb port of my PC(desktop).

Any help..much appreciated

Devan

(e-mail address removed)