How to fix your PC when it doesn’t want to boot and goes on and off

Fixing PC on and off issue

I just fixed a PC where I had this issue of; when I switch it on it would sometimes boot and sometimes go on and off till it reached a point where it barely went on. I had several PCs running on the motherboard MSI H61M-P20 for socket LGA 1155 CPUs. I have changed in 2 different PCs this motherboard and upgraded it with an MSI H61M-P31/W8 which is actually not that new any more component configuration wise and difficult to get on the local market. I was happy to get one at the intel agent shop in Grand Baie. Sometimes in small computer shops in villages you can still get older spare parts! Try your luck that way if you need older parts.

I like MSI mainboards when it comes to building Ubuntu Linux office Pcs as I had the least trouble with them except that some of them like the P20 has a short life time, they only last up to 2 years (daily usage implied). The P31 seems or is a bit more robust as I have 3 of them still running and one since 3 years still doing good on i3 cpu with 8GB Ram + graphic card attached to 2 screens. With ASUS unfortunately I have had very bad experiences with Ubuntu but no issues for gaming in Windows.

MSI H61M-P31 W

Please if you are in Mauritius and have experience with other mainboard brands that you run on Ubuntu flawlessly, pls recommend to me in comments. My trouble shooting below is my way of fixing the problem in an amateur way. It’s my fix and not THE FIX. You can definitely do this in a more detailed way with checking the cables power supply voltages and all that but I have built so many computers that I’m quite bored fixing them, I just prefer when they just run! So I take the short cut of just doing the routine below. I will add some other references to look at, at the end of the article. If you want to take it further you might also want to get some Debug cards. Jacey Computer in Port-Louis does sell these or you order some from China.

MSI H61M-P20

Now let’s look at the problem of the PC that doesn’t want to boot and goes on and off.
1. Usually when this problem happens, the first thing I do is that I check the power supply unit. If I bought a cheap PC, quite often it will come with a very cheap power supply unit and sometimes they also have rust at the back. For several PCs when I replaced this device (PSU: Power supply unit) with a good PSU, you can get one for like Rs.1850 at Jacey in Port-Louis, the problem was fixed. But what do you do if you already have a good power supply unit and the problem persists? Keep in mind when you change something in your PC always to put the power off first! I will not give you detailed instructions of how to remove each part, you need to have at least some basic training/know how. It doesn’t take long to learn such basics.

2. I unplug the DVD player, re-switch on. If problem persists:

3. Unplug hard drive, re-switch on. If problem persists:

4. I remove RAM, re-switch on. If problem persists:

5. I remove the CMOS battery for a while and put it back. (But this step according to some reviews is not really necessary…) If problem persists:

This is the point where you could question if its the CPU/Fan, I will usually also clean up the fan first which could also fall under point 1. In most of my cases it has barely ever been the CPU that caused this issue. (Please also consider that you computer might be overheating…) At this level I’m more certain that it is the motherboard. (My cases)

To avoid buying a new computer I try to check with vendors if they still have a similar mainboard or at least a motherboard (it’s the same like mainboard, I just swap words at times!) with the appropriate socket where I can use my older CPU. In this way I manage to fix my PC at around Rs.3500-5000 instead of buying one at +Rs.15 000. And then it runs again for some years.

For me this method has worked several times.

Usually when I buy PCs I make sure to get it with a good Power Supply Unit. I like the black Thermaltake models at W450-550. There are ofcourse even better ones. If you have lots of energy consuming items in your PC like a heavy duty gamer machine, you will need more than W550. You can add up how much watt all your items use before buying the right power supply unit.

What I hate during the motherboard installation is installing the cooler fan, quite often you have to do a lot of pressing till your thumbs ache!

I would also recommend if you can get some special gloves when you work with computer spare parts. On one side it will protect you from mean cuts and also from static electricity that you may pass on to spare parts.

Please also share your experience of fixing computers.

I haven’t tried this yet, but if you have this on and off going issue, it could also be that your motherboard is having a short circuit due to contact with the metal casing. So before doing what I do, try to get cardboard washers between the screws where they have contact with the motherboard or get plastic mounting at your computer shop.

One other way you can test your motherboard is by removing it from your PC and you place it on a surface like wood and then power it back on and see if then it works. I will do this test next time when I get this problem again. As you can see there are many ways to approach this issue. Am also pondering to get one of these debug cards…

Check out this nice debug card tool with display!

Where to buy?
In Mauritius @Jacey Computer Systems LTD
POWER SUPPLY TESTER (PK 3000) at Rs.626 (2016)
PC ANALYZER DEBUG CARD PK-1049 at Rs.176 (2016)

Wholesale PC Analyser Card

PC Repair Tools

It took me longer to find and compile this list of videos than writing my post! Hope you enjoy the selection! There are also some nice technical videos out there in Portuguese and Hindi, not enough videos for PC analysis / diagnosis tools.

What To Do When Your PC Shuts Down At Random

ATX PC power supply diagnostic and repair.
In this following video it’s interesting to see how this technician repairs a cheap PSU, this is the kind of model you get quite often in cheap PCs in Mauritius. I personally wouldn’t invest in such a model, from experience they usually have broken down within 1 year. They cost like Rs.400-500. Better you get a good one because once, one exploded in my office and it was a super loud bang scaring all my work colleagues!

Computer Power Supply Tester with LCD Screen

Thermaltake Dr. Power II

PC Motherboard Debugging cards for beginners

I will NOT be held responsible for any damages of the methods mentioned in my blog article may cause to yours or someone else’s computer, hardware, software, and/or data, including loss of use of such devices and/or loss of data and/or loss of profits from the resulting inability to use such devices and data. Any information or program you choose to put into use from my blog is done AT YOUR OWN RISK. As a precaution, I recommend backing up any irrecoverable data before practising any of the methods mentioned in this article and blog.

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