PC turns on and off repeatedly after pressing the power button.

[Miyuru Gunaratne]

Hi all,

This is the first time I am using this forum to get a problem solved. I have searched Google for many days to get a solution but all those attempts were in vain so I decided to post my question here in hope of getting a great solution for the problem that doomed me.

My PC tech specs

• 
  Dual Core Processor 2.5 GHz
  2GB DDR3 Ram
  500 GB HDD
  768 MB Intel HD on-board Graphics
  Operating system Win 7 Ultimate 32 bit,
  PC model : HP p2 1410l

The Problem is as follows:

The computer that I used was a brand new HP computer. It worked fine for 8 months and then showed up problems, The first problem I got was. When I press the power button of the PC it lights up then after few seconds it turns off and then turn's on again this happens several times (There is nothing on the screen) and then the PC boots normally. When it boots nothing happens thereafter. I can use the computer as a new one. But the worried part is It takes a long time to switch on the PC like this, then I contacted support and they sent a technician who pulled out the ram and cleaned the edge of the ram with a rubber eraser after that the PC switched on at the first attempt. Which made me amazed and surprised. After that the problem was solved.

Then after working for another 4 months again the same problem occurred but unfortunately this type it didn't get solved after I did the same thing the technician did last time. I switched the ram between the two slots, checked all cables but nothing got the PC to turn on. I was so worried after trying many times to get the PC running. This time when I press the power button the power light and the HD light turns on fan's running and within a second the PC turns off ( nothing on display) and then again automatically the power light lights again with HD and fans running then again it switches off, This happens several times repeatedly gradually as this happens at one time the power light tries to stay light up a bit longer but the HD light doesn't light up. fans running. again it switches off automatically with a few seconds more than earlier. After many on's and off's the PC boots up normally after long time. After the PC boots nothing happens until the next power up. Again the same way I had to wait for a long time until the PC switches on successfully. So I thought this would be OK since the PC boots fine after many on's and off's after pressing the power button. But that was not OK since after switching on the PC for the third day, The PC's power button didn't light up at all but the HD light and the fans were running ( nothing on screen ) This time I had to press the power button to switch off the PC it doesn't turned off automatically as it did earlier. Sometimes when trying to turn on the PC the CPU fans runs but not the casing fan and also the CD Rom did not work this time (the tray did not come out) . I switched off the PC again without any hope. All attempts were in vain.

I think the things have become worsen day by day when I tried to switch on the PC. Now when I push the power button it light up and the turn's off within a second. fans working it doesn't turn on automatically now I have to press the power button to turn on it but it turns off's automatically within a second. Now the situation has worsened. The PC doesn't turn on any more. I am so frustrated and out of luck this time since it doesn't boot anymore. 😱. I thing this would be an unusual problem for you all too. Anyway I hope for a good respond for the situation I have faced. The sea is close to where I live only a few miles. I am near a river bank. where the sea is towards West few miles from where I live. So salt has accumulated on my Motherboard.

I think the problem is due to accumulation of salt on the motherboard but I am not sure about it.

PS: My PC doesn't have a PSU but the power cable has an adapter on it which I thing that is the PSU I may be wrong maybe, My PC requires only a small DC current to power up. It only uses 22W per hour when in peak operation.

I hope that I have posted the problem in the correct category.

Thank you for taking the time to read my problem.
Any support would be greatly appreciated

Regards,
Miyuru.

 

[C12Friedman]

I'm just a bit confused here, you describe your PC as a Small Form Factor yet the link is to a Mid-tower PC. A mid-tower will not have a power adapter while an SFF would.
Regardless I'm pretty certain your issues are related to power. May be the power distribution board inside the PC, could be the adapter itself. If still under warranty contact HP again for service otherwise your best bet (IMO) would be to find a local shop that can help figure your problem area. Or, you could simply swap out the adapter hoping that's the problem and then the power distribution board and then the...

 

[Miyuru Gunaratne]

Thank you for your response. Sorry for misleading you by the incorrect information. Yes, indeed my computer is a mini tower which doesn't contain a PSU in it, but has an adapter with the power cable to power up the machine. The link that I gave is the machine that I have. It's the correct one. I may have gone wrong in the description regarding the problem. I am sorry for that.

Luckily the computer is still under warranty from the company where I bought it. I took my computer to a repair shop as you said. There it worked finely without an problems with the adapter. There aren't any issues with the adapter at all. I think the problem is related to the current in our home. I think the earth wire is not properly earthed to the ground. But, although the earth wire isn't earthed the computer worked finely for almost a year. This is the first time I saw a computer without a PSU. The power is directly supplied to the motherboard.
The thing I am worried is that would issues in current affect the motherboard. There were many power failures. Unfortunately I don't use a UPS still. I think that would also lead to a negative affect on the motherboard. There is salt accumulated in the motherboard since I am near the seaside.

Anyway, the warranty given by HP is over. But, I still have the re seller warranty.

I am not sure what you meant by this.

May be the power distribution board inside the PC, could be the adapter itself.

There is a separate adapter which converts AC to DC while lowering the voltage which then enters the motherboard where it gets distributed to all the components the required power for each of them. This is the strangest motherboard I have ever seen. It does the duty of the PSU too. 😀

Thanks again for you support. I appreciate it a lot.

 

[C12Friedman]

That is a strange system. Having it work properly at the shop I can only conclude that the power in your home is too wonky for the adapter to deal with. Have you tried other outlets in the house and have you (or anyone) checked the actual voltage range of incoming current to the house. I'm considering that a capacitor may be blown - was the computer off for any length of time before taking it to the shop? If there was little time between the computer running and it going to the shop, a bad cap may still hold enough of a charge that it doesn't go through a cycling event to get charged. You can look over the motherboard for any leaky or swollen caps.
I'm kind of at a loss here, would it be possible for you to post a picture of your mobo (notably the area where the power comes in and the black capacitors above the CPU)

 

[hang-the-9]

You said there is salt on the motherboard? That is not good at all, salt is a good conductor in addition to causing corrosion which means that it will end up shorting components.

The system may very well have power issues that were not seen when you brought it in for testing because some power issues only show up after use for a while. You let the system rest, and then it works OK for a few hours. Then you can't turn it on again till it's cooled off for a bit.

See how much a new power adapter for the system is. While pretty old, that system is not useless, it has a decent CPU and DDR3 RAM. If it was any older I'd just say get rid of it and get a replacement system, in your case, it could be worth just trying a different power supply. Although if there is really accumilation of salt on the motherboard, I'd replace that first.