Hi guys. So I unplugged my PC for about a week (outstation). When I come back home, it won't turn on, the power led was on and fans were spinning for half a sec then it just shuts off.

I opened the case. Basically reconnecting everything, and it started again normally. I thought it was just the mobo power cable connection. I even game on it for a bit this morning. Suddenly, just after finished gaming (game closed already), the pc shuts off by itself, and tries to start back up and fails again in a loop.

Any ideas?

Do you have a spare PSU to test it on your pc?

Not currently. Planning to borrow a friend's but his is only a 250w. Is it enough for a i5-3470 and a 7870?

For just i5, is enough, with 7870, no. So, u may need to test your PC with onboard display if using your friend's 250w.
If u just want to get it bootup and load into windows, u can get yourself a pair of molex 4 pin to 6 pin converter, beware that if u do this, this is just enuf for idling, if u go and start a game, that could fried your friend's 250w instantly.

Yeah, I just want to isolate the issue to the psu.

Hi sifus. An update here. I tested my pc with a friend's psu. An aerocool 550w 80+ bronze and it still does not work. Does this mean the problem is not psu? Any ideas on the next step?

- swap graphic card or try using onboard if available
- reset CMOS

When u say unplugged when u left your PC for outstation, what else cable still being plugged ? Like LAN cable, VGA/DVI cable or 3.5mm audio jack ?

Reset cmos even if I did have never messed with the bios?
Everything else was plugged. I only meant the power to the psu was off.

This post has been edited by Ronin_Amin: Nov 30 2015, 06:52 PM

Restart loop?
Could be HDD problem either Windows is corrupted or motherboard can't detect the HDD.

You can download the HDD diagnosis program from the HDD maker site.

This post has been edited by WebWalker: Nov 30 2015, 06:56 PM

A lot of things could happen, no harm giving a try, it will just reset all the setting back to default.

Well... Is rainy season, that means thunderstorm, while u were not at home, your PC could have been surge damage, power off doesn't necessary means surging won't found its way into your PC.

Yeah the surge damage is one of my concerns. But wont the psu be fried first?

It can damage both your psu and mobo as well. U using LAN as internet connection ?

Yup. Lan as internet connection. So just to confirm, since I used my friend's PSU and it still doesn't start, my PSU is fine right?

High chances are still fine, u can do a simple test by shorting green color to any black color wire to confirm. By shorting it, it will turn on the PSU, if fan are running most of the time it is fine.
http://aphnetworks.com/tutorials/psu_paperclip_trick

Yeah the psu fan is still running. I just used the normal method to turn it on.

This post has been edited by Ronin_Amin: Dec 1 2015, 02:13 PM

Is it considered a restart loop it it just turns on the fan for a sec and then the power led lights up and everything turns back off and the whole thing starts again? Monitor does not even turn on.

check your system to see if there are any dead lizard or cockroach inside. Maybe it is causing the problem.

I have already reopened the system and reconnected all the cables. Nothing unusual was found.

suspect dead cmos battery
replace a new battery, it just few ringgit only
buy for backup oso can

cmos died due to lightning? Where to buy cmos? All mobo same cmos?