Faulty PSU?

Johnny-Kun on 02/07/2013 - 15:15
Last edited 02/07/2013 - 15:25

My friend's computer is acting up, said it constantly rebooted and didn't show any boot screen. Hasn't used it for 2 weeks, I went over and checked it out. First thing I made sure was if the plugs and cables were connected properly before turning it on. It booted up and worked, I thought it might have just been a loose power connection to the computer.

A week later, he calls be again and said the computer was having that same issue again, I came over and had a look. Turned the computer on, everything would power up but after 1 second or so the computer would automatically reboot and go on a rebooting cycle. Everything seemed to be powered on, either way I took it home to inspect it some more.

I was busy for almost a week and finally gotten the chance to have a look, opened it up and cleaned the computer. Double checked the cables and they are all fine, pressed the button to turn it on and it works, loads into W7 and all….

Its very strange and was thinking that it might be a faulty PSU, just wanted to get someone's opinion before I go out to Umart and pick up a Corsair VS650. The PSU is probably just over a year old "Thermaltake", came with the case.

Computing

Comments

  • kermuffle on 02/07/2013 - 16:02

    i used to get the same problem with the rebooting, and found that pulling out the power cable from the power supply, waiting a few seconds, then putting it back in stopped the reboot cycle.

    if it's not that, it might be useful to take the motherboard out, and unplug and replug al the power cables and connectors. sometimes a screw or something metallic could be shorting something out. failing that, i'd rma it if the warranty is still valid.

    • Johnny-Kun on 02/07/2013 - 17:26

      I'll be doing some cable management on my mates computer, hopefully it might solve the issue. As for rma, he doesn't have the receipt anymore so I couldn't check and see if the warranty is still valid….

  • _Bruce_ on 02/07/2013 - 17:01

    I'm not clear on when the PC reboots. If it is after starting to load windows make sure the automatic reboot option is turned off. This will at least show you what the blue screen is.

    • Johnny-Kun on 02/07/2013 - 17:19

      Well the PC is working after leaving it alone for a week since I was busy. I've done what you've said and turned off Automatic Reboot Option. I'm going to do some cable management on the PC and zip tie everything so its neat.

      I'll leave the computer running for a while to try and mimic the issue that I saw earlier last week which was the rebooting cycle.

      When you turn the PC on, all you get is a black screen, the fan would spin for a second or so and the PC would turn off and then turn on again, goes on a cycle.

      • _Bruce_ on 02/07/2013 - 18:49
        +1

        OK this isn't automatic reboot then. Do you have a PC speaker attached? You might get error codes out on the speaker. Otherwise check for flashing light codes and check the motherboard manual (they are pretty easy to find on the internet.

        In my experience this is generally caused by a CPU/Memory fault. Possibly one of the memory sticks is not making good contact but shifts slightly some times and works. This can also happen with a hair line fracture on the motherboard. From the information I have I would think these are more likely that power supply.

        • Johnny-Kun on 02/07/2013 - 19:11

          ah okay, I'll probably strip the PC apart and re-assemble it. Might put some new thermal paste for the CPU while I'm at it, cant see any fracture on the motherboard but I'll do a thorough search when I finish work tomorrow.

          I've cleaned the computer, made sure all the connection plugs/wires are properly fitted, installed an extra fan and hooked it up.

          It doesn't have internal speakers and I have yet to mimic the problem to be able to see any flashing light codes, seems to be working normally after being on for 4 hours.

        • scrimshaw on 02/07/2013 - 19:46

          You should also perform some form of memory and hard disk diagnostics while you're at it. Just in case it's a faulty RAM module or a hdd that's going bad.

          Try UBCD.

  • Johnny-Kun on 03/07/2013 - 14:42

    I pulled everything apart and installed everything again, New CPU Thermal paste and cleaned everything so no more dust.

    Turned the computer on and managed to get the reboot cycle going, got my PSU from my computer and hooked it up to my mates but still got the same results. I then removed one of the RAM on the secondary slot and noticed it was different to the other two.

    Turned the computer on and it booted up again, sounds like that RAM stick is faulty.

    • _Bruce_ on 03/07/2013 - 18:10

      Could also be the slot or a bad contact.

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