UPS - PowerMust 1000 Offline

[Beric_Dondarrion]

Last month I had problem with my PC. PC would suddenly turn itself off (without goodbye screen), sometimes it would freeze during work.

I've tried everything. I've disconnected it from UPS, measured it's temperatures, checked PSU, ran Hiren's Boot for a couple of times... Everything was "ok". But the problem persisted (PC would shut itself down after 30 min or 30 hours of work, during hard work, or being idle).
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Believe it or not, it's working now for 12 days without problems! It's still disconnected from UPS. It started to work normally when it was disconnected from UPS for about a week (like PC recovered from something during that time - Is it possible that PC needed time to recover from bad UPS?).

My UPS is 3 years old and from when I bought it, it was very noisy when its batteries were full. Some high pitched humming noise... And, when power goes off, PC gets its power from UPS. That's the moment when Power Supply Unit becomes noisy too! Some kind of crackling noise. Serviceman said "it's ok" (told me something about sine wave output...).

Now, should I reconnect PC to UPS... I don't know if PC would start shutting down again...

Thanks.

 

[leal]

Psu

theres is a troyan shutdowner running around I had a similar problem in both of my PC's, after some time it would shut down for no apparent reason or it could be time perhaps for a new battery.

 

[leal]

Ups

theres is a troyan shutdowner running around I had a similar problem in both of my PC's, after some time it would shut down for no apparent reason or it could be time perhaps for a new battery.

 

[Beric_Dondarrion]

I've heard of that Troyan, but Malwerbytes' didn't find anything.

Thanks, leal, but I don't think UPS battery is what's making problem... That can't explain shutting down when PC is disconnected from UPS...

Any other suggestions?

 

[ben7]

Last month I had problem with my PC. PC would suddenly turn itself off (without goodbye screen), sometimes it would freeze during work.

I've tried everything. I've disconnected it from UPS, measured it's temperatures, checked PSU, ran Hiren's Boot for a couple of times... Everything was "ok". But the problem persisted (PC would shut itself down after 30 min or 30 hours of work, during hard work, or being idle).
_______________________________________________________________________

Believe it or not, it's working now for 12 days without problems! It's still disconnected from UPS. It started to work normally when it was disconnected from UPS for about a week (like PC recovered from something during that time - Is it possible that PC needed time to recover from bad UPS?).

My UPS is 3 years old and from when I bought it, it was very noisy when its batteries were full. Some high pitched humming noise... And, when power goes off, PC gets its power from UPS. That's the moment when Power Supply Unit becomes noisy too! Some kind of crackling noise. Serviceman said "it's ok" (told me something about sine wave output...).

Now, should I reconnect PC to UPS... I don't know if PC would start shutting down again...

Thanks.

Maybe the UPS output voltage is saging, causing the computers' power supply to shut down.

Also check to see if your UPS is underrated!

 

[Beric_Dondarrion]

UPS was working fine for about 3 years, and, yes I've checked it, it's strong enough for my PSU.

Thanks, ben7.

 

[ben7]

Time to open up the computer to see if there are burned spots or bad capacitors.

 

[Blars]

It also could be overheating. Fans can go bad, or it could just be clogged with dirt.

 

[Reloadron]

My overall experience with UPS units is the batteries last for about 2 to 3 years. That is about when I find myself replacing them around here. This caught my interest:

Believe it or not, it's working now for 12 days without problems! It's still disconnected from UPS. It started to work normally when it was disconnected from UPS for about a week (like PC recovered from something during that time - Is it possible that PC needed time to recover from bad UPS?).

So what you are saying is that when it was initially disconnected from the UPS the problem persisted but after a week the problem went away. I don't see the PC "recovering" over a period of time from a bad UPS.

Generally a contributing factor to sudden reboots or shutdowns can be temperature, thus a first step is cleaning things out. Making sure all fans are rotating and paying attention to the CPU HSF (Heat Sink Fan). Make sure the CPU HSF assembly is free of dust and dirt. On older systems it can be advisable to remove the HSF and throughly clean the CPU surface and reapply some heat sink thermal compound or thermal interface material.

Throughly inspect the motherboard and graphics card paying close attention to the capacitors. Look for buldging or split on top capacitors as well as leaking capacitors. I have a graphics card laying here with several split caps that was causing shutdowns. I am surprised the thing worked as well as it did.

Finally the PSU itself can't be ruled out as a problem. The PSU itself can be a little more difficult to troubleshoot beyond taking some voltage measurments and that doesn't always tell you much.

As to the UPS. They come in several flavors and output a few waveforms. The most common off the shelf UPS units output a modified square wave and for the better part do what they are supposed to do. They only switch to the modified square wave output when mains power is removed or fails. Since your problem persisted for awhile after the system was removed from the UPS I would not be too quick to fault the UPS. About all you can do at this point is wait and see if the problem returns. That and some of the visual inspections mentioned.

Ron