PC restarts when electricity goes off

I'll explain everything for you:

Inside the PSU there is tow big capacitors that filters AC input to the PSU and hold a charge in them, whenever electricity suddenly got spikes or drop it's voltage, those capacitors discharge in milliseconds in the input line to keep the PSU running till AC line get back to normal...

The capacity of those capacitors was calculated to handle the PSU's full power for "X" milliseconds...

Now for the UPS, when electricity drops suddenly or goes off, the UPS will automatically switch to the battery using relays..

The relays in the UPS needs "Y" milliseconds to switch over...

Now in simple words.... if Y >= X then PC restarts or shuts down !! (if the discharge of the PSU caps is faster than the speed of the UPS relays then the caps will become drained before AC line get back to normal and there's nothing to feed the PSU)

Simple !

To fix this you must make X > Y witch means that you need faster UPS relays "Y" (bigger and better quality UPS) or get a high "X"

If your PSU is lower or barely power-up your system then the caps will discharge extremely fast "X"

To fix this :
1- Get a bigger PSU with more watts
or
2- Lower your system's power needs

First, make sure your UPS is running fine and has no problems, remove your VGA and run your system then cut AC power, if your UPS switches to battery and your system is still running then it's fine, if not then your UPS is bad..

Assuming that your UPS got an overload protection, you can do a small test to know the cause of your problem (UPS or PSU) :

While on AC power, run a super heavy 3D benchmark capable of pushing both your CPU and GPU to their limits..

That will put your PSU on a heavy load

1- if BSOD - get bigger PSU
2- if restart & no UPS overload beep - get bigger PSU
3- if restart + UPS overload beep - get bigger UPS
4- if shutdown (PC&UPS) - get bigger UPS
5- if shutdown (PC only) - get bigger PSU
6- if UPS overload protection beeps - get bigger UPS
7- if system lockup or freezes - get bigger PSU
8- if strange colors/lines/objects appears in the benchmark - get a bigger PSU

best regards

Hi Mohammed. Thanks for your explanation, I got the idea. Actually, I tried removing the VGA before, and the UPS seemed to be fine: no restarts, not shutdowns. So I knew that it's consuming a lot of power, plus all of the shutdowns took place while I was playing games, so more GPU consumption.

Anyways, I would like to tell you guys that my problem is solved. Don't ask me how, but I did 4 things at the same time, so I don't know which one did the trick. Here's the list of what I did:

1- I changed the old electricity extension (or rallonge). That was a pain in the a** because if I barely touched the cables, sometimes my screen or router would turn off. They were very sensitive. So I assume that might be the most important factor in the solution.

2- I didn't use the electricity cable that came with my new PSU. It's the same as the one I had, you know the black thick cable ... I thought why not try a new one.

3- As AvoK95 told me to check the manual (I did before), but I rechecked it again to find that there's a serial cable connection still in my UPS box which I haven't used. I don't know if it's important, but I connected it to my PC too.

4- The last one is a weird and funny one. I did as Julien Saadeh said in the 2nd page of this thread, I put the UPS on the floor instead of where it was (on the table).

However, the solution is not a 100% solution. I figured that while on desktop, my UPS can handle the PC while electricity is off, but when I was playing a game, the UPS gave the normal beeps for 30 sec maybe and then started to give fast beeps. Anyways, it's enough time to let me turn off the PC in case the generator didn't come online. It's still way better than before where the PC would shutdown directly when the electricity went off and while playing games.

Anyways, thanks for your help guys.

AvoK95 wrote@MohammedSF,
Great stuff you got there !

Thanks AvoK95

PC_47 wrote1- I changed the old electricity extension (or rallonge). That was a pain in the a** because if I barely touched the cables, sometimes my screen or router would turn off. They were very sensitive. So I assume that might be the most important factor in the solution.

Thank god that it didn't start a fire !

Well i suspect #1 or the weird #4 (only if your UPS is metal covered)

I'm not an electrician but it might be your old UPS is routing electricity in a way that made your PSU malfunction, and putting your UPS on the floor is the same as grounding your hall system, good idea from Julien Saadeh, but only if your UPS's metal cover touches the floor.

You can check if your UPS has any leaks by standing on the floor with bare foot and touching your UPS's metal case, if you got some new brakedance moves then here's your problem right there hehehe

PC_47 wroteHowever, the solution is not a 100% solution. I figured that while on desktop, my UPS can handle the PC while electricity is off, but when I was playing a game, the UPS gave the normal beeps for 30 sec maybe and then started to give fast beeps. Anyways, it's enough time to let me turn off the PC in case the generator didn't come online. It's still way better than before where the PC would shutdown directly when the electricity went off and while playing games.

if you can run a game for 30s on a 550va UPS with a 560ti then "بوس ايدك شعر و دقن على قولة اللمبي" hehehe

Because if i fire-up any game, the main 5A's generator switch cut-off and if i use my PCE 1000va UPS i can't even run 1s on my 60A battery !

hehehe well 1 strange thing happened today while I was playing Dirt: Showdown, the UPS gave a long beep and my PC shutdown along with the UPS. I did a benchmark yesterday like u told me using Dirt with everything maxed out and got pretty much good FPS (around 36 avg FPS) and nothing bad happened ... today my PC gave up I guess with those maxed out settings :P hehe so I just reduced the multisampling. Anyways, my PC is still alive and running well :D tomorrow I'm getting a new DVD drive because I suppose "nlatash" the old one as a friend was trying to put my new VGA on the old PSU while I insisted that it needs a 500W PSU "la la btemshe" -_- he couldn't even connect it to my old PSU because it doesn't have 6pin connectors, he wasn't in his shop and he had a kid do it (tkheyal rakkab l vga bala ma yousal l 6pin connectors, aslan he can't on the old psu, so l arja7 nlatash dvd drive mni7 mish shi tene) ... anyways, I'm dying to install and play Battlefield 3 tomorrow (sarle zamen zamennn nater hal la7za :P haha) yes, I bought it since it came out, but I didn't even have windows 7 back then until recently, and finally I got a good GPU; great actually, but I hope my PC won't explode with Battlefield 3 :P

edit: btw it's definitely not a 550VA ups :P plus i have 10A at home :) ba3don 7emlin :P

Well, i hope you battlefield well..

My old system based on a Q6600 running 3.6GHz and GTX285 SLI powered by a Gigabyte Pro Odin 800w PSU, believe it or not I can't play anything on "ishtirak 5A" -_-

As the hall country suffers bad electricity now, I haven't run a game on my PC since April 8 !

I'm building my new system now, am just waiting for GTX690 prices to drop "1000$ WTH" if it's not dropping within 2 months am going with the GTX680..

julien_saadeh wroteThe long beep means that the ups is overloaded. Common in PCE.
About my weird story, no the ups isn't metalic. It's made of plastic and probably had a wooden table phobia? (By the way, I still have it :D)

I've seen a PC that has a Caseophobia once !
a system that works fine on a table (outside the case) but won't post inside the case..

I love those weird hardware things that make me scratch my head wasting +10 hours trying to figure out wth is wrong with this pos ! hehehe

PC_47 wroteI have Q6600 too but 2.4 GHz. Concerning 5A, I know ... we used to have 5A before 10A. I imagine you understand now why we switched to 10A :P This is Lebanon my friend, what can we say.

I know i need 10A minimum but wait... here it's 350.000L.L/Month now and it's too much for me -_-

MohammedSF wroteI know i need 10A minimum but wait... here it's 350.000L.L/Month now and it's too much for me -_- !

Yea and sometimes even a bit higher!

I have a question btw: will the dvd drive affect how things are working now for me ?