Pc Only Boots After Several Power Button Presses And Keeps Shutting Down And Restarting

Hi all - looking for advice please.
Since last week when I press the power button to switch on the PC it takes severall attempts of pressing the start button before it actually begins to boot up.
I have had exactly the same issue today but the PC has also twice so far just shut down and restarted itself whilst I was in the middle of working. The PC is not old.
I know there was a Windows 10 update last week so I dont know if this has caused the problem.
What is the best program I can install which will scan for issues on my PC and fix them automatically? ( is there such a program which can do this eg scan registry for issues etc? I'm a bit wary of doing this myself.
I've tried Windows help but its not telling me what I need to do.
Thanks for any suggestions

 

This could be caused by several different things. Broken power switch, or loose cable for example. So I would unplug the computer from the wall, open the side panel and inspect the wiring to make sure every power cable is firmly connected.

Broken power switches are often not easy to determine by looking at them from the inside. But what you can do is follow the two wires from the power switch and see where they connect to the two pins in the motherboard's front panel I/O header. Note the two pins. Then follow the two wires from the case's reset button and note which two pins they connect to. Pull the wires from the power pins on the motherboard and insert the two wires from the Reset switch. Don't worry about polarity - it does not matter.

Then do a quick visual check of all other cables again to make sure you did not knock something loose. Plug in the power supply and this time, press the Reset button (since it is now acting as your power button).

If it boots up properly, you found your problem (bad power switch). If me, I would just use the Reset button from now on.

If you still have problems, note this is also a classic symptom of a power supply failure. So swapping in a spare PSU is the next step to see what happens.

Since the operating system (Windows) is not touched until well into the boot process, after the system passes POST (power on self test) and the BIOS seeks out the boot drive, I don't see how this could be caused by a Windows Update. And since this problem occurs at the initial stages of the hardware boot process, there are no problems that can troubleshoot the power button.

The only other possibility might be a bad CMOS battery. These are pretty easy to replace. Unplug from the wall, open side panel and touch bare metal of the case interior to discharge any static in your body. Carefully remove the CMOS battery, noting the polarity. It will be a wafer type, likely a CR2032, and be about the size of quarter coin. Replacement can be found at just about any battery/watch/camera counter at Wal-mart, or any home improvement store.

Do NOT touch the new battery with your bare fingers. Skin oils promote corrosion and attract dust. I put a clean sock over my hand. Insert the new battery, again observing polarity. Make sure you didn't knock any cable loose, connect power to the wall and boot (if the switch works) directly into the BIOS Setup menu by pressing the appropriate key during the boot process (typically the Del key or a F key). Check/set your date and time, make sure your disk boot order is correct (if you never changed this, it is probably good to go with the default), then Save and Exit to [hopefully] boot normally.

Good luck.

 

Hi Digerati
Thanks so much for your very comprehensive reply. The PC booted up first time with no problems this evening so maybe it has righted itself? I'm waiting to see if it keeps shutting down and restarting.
The information you have given is way beyond my capabilities so I will ask my partner or get a local Tech repair company to follow your instructions. Fingers crossed that there will be no need.
Thanks again

 

I hope it holds. To be sure, I recommend you make backups of any files you don't want to lose - just in case.

 

Hi again Digerati
I will certainly be doing this. Thanks again for your support

 

Spoke too soon Digerati. I have just plugged my external harddrive into the base unit to do a backup and the whole PC shut down again. It must have been the very small movement I made when I plugged the harddrive in. Do you think this suggests just a loose wire somewhere?
I've pressed the power button again about 8 times and got it back on and I am now frantically trying to back up everything before it becomes impossible.

 

It MAY suggest that your USB could be causing the shutdown. How old is this PC?

Make, model, and OS please.

 

Hi mekanic
This is a Novatech PC bought in 2016.- Windows 10. Today I noticed that the power cable was kinked at the back so I have replaced it. I booted it up for the first time after this and it worked first time. I will continue to monitor it as I'm unsure if this was the root of the problem.
Regards

 

As a test, plug in the external HDD.

 

Hi again. I did this last night and managed to do a full back up on the second attempt. Ive just plugged it in again but only a minute ago. I'll wait a bit and see what happens

 

I recall a "funny" about a frayed knot...

 

Leave it there mekanic it sounds dubious. Hope I dont get any more symptoms eh?