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[Resurrected! ] How to turn on a Desktop PC?

Discussion in 'Computers' started by Madasa, Sep 7, 2020.

  1. Madasa

    VIP Member Thread Starter

    I'll get the switch repaired when I can.
    Question removed.


    #1 Madasa, Sep 7, 2020
    Last edited: Sep 7, 2020
  2. Best Answer:
    Post #11 by rootabaga, Sep 9, 2020 (3 points)
  3. MoodyBlues

    MoodyBlues Compassion is cool!
    VIP Member

    Just a suggestion: don't delete it!

    I didn't see it in its original version, but I've deduced that your problem turned out to be the switch. The thing is, someone else may come along with the same symptoms you had, and learning that the switch needed to be replaced could be helpful for them.
    ocnbrze, MrJavi, mikedt and 1 other person like this.
  4. rootabaga

    rootabaga Android Enthusiast

    ...and here I thought you were going to say that if it was a Windows PC, being unable to turn it on is a security feature. ;) :D

    Seriously, I agree to leave it in place. Always useful in the future for the users who might use the search feature.
    Davdi, ocnbrze, MrJavi and 3 others like this.
  5. MoodyBlues

    MoodyBlues Compassion is cool!
    VIP Member

    Bwaaaaahhh! :D :D

    You do know me well.
    Davdi, ocnbrze, MrJavi and 1 other person like this.
  6. Madasa

    VIP Member Thread Starter

    Thanks. This is what I recovered from my OP.
    It's a really old pc, but I enjoy my music off it to headphones. That's all I use it for.
    Some crossed wiring or mechanical switch connection. It has to be inspected obviously, but I can't take it anywhere at the moment.

    OP :

    Electrical connection issue.

    I keep a 2004 desktop because I love the ripped cd audio sound from the 7200 rpm hard drive, coupled with an audio enhancer only out on XP. (using Grado headphones).

    My Lenovo Thinkpad Laptop and Nokia phone have completely uninvolving sound by comparison, so I miss it, though I listen to music less than I used to.

    Developed a front switch issue, intermittent at first. I can't transport it to a previous good repairer without a car now and funds are low for a few weeks.

    When it's working normally, and the mains override? switch at the back power socket is left on, it would only come to life when I depress the circular front switch with a back light (blinks slowly on Standby, lit when running).

    Now when I switch on the mains switch at the back, the fan comes on and the light behind the large front power button fizzes silently. The hard drive doesn't spin. The button physically clicks in normally but never turns on the pc. (except occasionally at first).

    I guess it's a soldering or motherboard issue. I can't get into the front plunger type switch mechanism between two panels, just the wires inside the case.

    Any simple fix? Thanks for reading.

    IMG_20200905_002442.jpg IMG_20200908_220012.jpg IMG_20200905_002553.jpg IMG_20200905_002645.jpg IMG_20200905_002514.jpg IMG_20200905_002609.jpg Screenshot_20200907-172549.png

    Yes! Old and dusty!
    I know I am, as is the inside of this pc :)
    #5 Madasa, Sep 8, 2020
    Last edited: Sep 8, 2020
    MrJavi, MoodyBlues and mikedt like this.
  7. mikedt

    mikedt 你好

    My thought for a PC from 2004, is possible capacitor problems. Because that was around the time of the capacitor plague.
    And I had a main-board fail with bad caps, that was originally bought in 2003.

    You may want to visually inspect your desktop main-board for signs of any caps in distress, like bulging or leaking.
  8. Madasa

    VIP Member Thread Starter

    OK. It's not just the front switch not fully disconnecting then. Yeh, probably makes sense what you say.

    I must say, if I had known in 2004 my £1000 pc would only last until 2020 I'd have given them a piece of my mind.

    I'm writing to my local MP to get my money back, I really am.

    ..... "Disgusted" of Tooting Bec

    (do your own Monty Python voices)

    I'll look at the board later tomorrow, I have an early start. Maybe if I stare at it hard enough....
    ocnbrze, MrJavi and mikedt like this.
  9. mikedt

    mikedt 你好

    If the whole computer is from around 2004, could also bad caps in the power-supply.

    Sometimes bad electrolytic caps don't always show visual signs of failure, and can only really be tested properly with an ESR meter.

    The symptoms I had with mine, was system instability with unexpected crashes, as well as it sometimes wouldn't turn on.
    Madasa, ocnbrze and MrJavi like this.
  10. Davdi

    Davdi Android Expert

    I guess I missed that with the one I built in 2009, Still going strong running Manjaro.
    Madasa and MoodyBlues like this.
  11. MoodyBlues

    MoodyBlues Compassion is cool!
    VIP Member

    As is my 2004 HP running Kubuntu. :)
    Madasa and Davdi like this.
  12. rootabaga

    rootabaga Android Enthusiast


    Please read through this before you actually do anything and post back with any questions if you're unsure about it.

    The front cover will actually come off. It's probably got a few "hidden" plastic tabs/tangs accessible from just inside that metal frame and it will either snap loose completely or be hinged on one side.

    Once it pops off you'll be able to see clearly which wires go to the power switch. Make note of them.

    FWIW, the I/O switch on the back of the Power Supply simply turns it on and energizes its coils. I am pretty sure that is an ATX power supply and it looks to be pretty generic. Hard to tell since there is not enough detail in the pics especially of the connectors and the MB layout.

    Once the PS is turned on via that I/O switch, the transformer comes to life so it's ready to go, and just a wee circuit on the MB is powered. When you press the power switch, it simply closes that circuit on the MB (think of it like a relay), which then fires off the rest of the circuits and power is supplied both to the MB as well as the drives, fans, ports, etc.

    There are roughly three possibilities. The easiest to check is the front panel switch itself. Once you figure out which pair of wires goes to that switch (pop off that front cover!), trace them to the motherboard. They will connect to two little metal posts and should just have a little connector for them. Turn on the I/O switch, then NOTE CAREFULLY where those two wires attach, then lift up the connector. You should not have to remove it all the way, but if you do, that's the "note carefully" part so you don't miss where it belongs. Once you have exposed the bottom part of those two posts by lifting the connector a little, you can then use a very small piece of metal (tweezers are fine but you can probably also use a straightened paper clip) with the end you hold covered by electrical tape -- this circuit is very low voltage and current, but just in case you touch something you shouldn't -- and short those two posts (and only those two!) together. That's the same thing as what the switch is (or should be) doing.

    If you hear lots of "familiar" noise then you know the problem is the front panel switch. Most are just a momentary on/momentary off, so you can find a suitable replacement online. It won't look pretty but you won't care, right?

    If, however, shorting the posts does nothing, push the connector back down, as the panel switch should be okay, and I would next try swapping the power supply itself. A used one is fine, and "generally speaking" you just want an old, basic ATX power supply (easy to tell that one is old because it has no SATA connectors, but it does have a floppy connector). Based on the PN in your pic that's only a 250W, so be sure you get at least that. If you have a computer repair store in your area they probably have a bunch of used ones laying around they'll part with for a song. Make a note of all of your connectors and replace them one at a time. You may not even have to remove your existing one if the replacement one has long enough wires. Once it's all connected, then plug your AC power cord into it, if it has an I/O switch turn that on, then press the front power button while crossing your fingers.

    If that doesn't do it, then the third possibility (now almost a certainty) is the mainboard. Since you won't be able to find one (if you do it will be someone like you that has it because they want it, so they won't part with it) and if you do it will be costly, then just buy an old XP computer. They are all over ebay. Then plug your hard drive into it and copy your music files (from whatever drive letter that shows up as) to the C drive on the "new" computer, and you're good to go. Copy them to a thumb drive as well since the drives are always a weak link. Note: You won't be able to successfully swap your drive in place of the drive in another XP computer and have it work, so don't bother trying. Even if it boots it will not be reliable. Just use your old drive to copy off your music and other files you want to keep.

    Overall, if it's not that front panel switch, you could just jump to getting another XP box instead of trying another Power Supply. That's probably what I would do in your circumstances (though in mine, I'd dig around in my pile of crap until I found another PS).

    Good luck.
    MoodyBlues, Madasa and Davdi like this.
  13. Davdi

    Davdi Android Expert

    Been there, done that, got the T shirt. That's exactly the way I want about it, In my case it was the case switch, but as I had some spare cases, I simply swapped everything over into one of the spare cases.
    Madasa and MoodyBlues like this.
  14. Madasa

    VIP Member Thread Starter


    Thanks very much for all that. It's really appreciated.

    I''ll fiddle with it on a quiet day.

    I had been keeping an eye out at used desktops. (My laptop now has an almost permanent mouse, keyboard and monitor connected.)
    I worry slightly though I'll find it hard to replicate the sound from this pc. Except for the occasional slight overspeed, it's pitch perfect and I think I have a good ear.
    IMaybe adding an old sound card to something cheap will work.
    I have all or most of my music on cd or backed up.

    If I may I might ask your attention again to understand which end you meant, and the fan coming on when it didn't before :p - but another time.

    I did think those panels would separate further with a screwdriver. I haven't looked for those capacitors yet.

    I may have to buy a good phone first, and / or send my phone for warranty repair.

    I wont give up on it yet. If I can't do something using your guide I'll probably throw money at it for a 1 hour look over in the near future.
    #13 Madasa, Sep 9, 2020
    Last edited: Sep 10, 2020
  15. Madasa

    VIP Member Thread Starter

    Thanks for restarting this @MoodyBlues .
    I was hoping for a magic wand scenario but Hey Ho :oops: :)
    #14 Madasa, Sep 9, 2020
    Last edited: Sep 10, 2020
    MoodyBlues likes this.
  16. rootabaga

    rootabaga Android Enthusiast

    The whole front panel should separate from the frame. It's probably a single casting with indentations, etc.

    The fan won't come on until the switch basically signals the "relay" to close and power the rest of the circuits, so fan, drives, etc. Since you said it was intermittent and slowly got worse that does suggest it's the switch and my fingers are crossed for that. The bypass test (shorting the pins on the MB) will answer that in short order.

    The end I meant is the mother board end. When you trace the wires you should come to some connectors that will look something like this:


    And in fact, looking at that picture, I suspect that the colors will be the same and the pair you want to trace is the green/white set (so you wouldn't have to pull the panel).

    This is kind of like how the pins/posts will look on the mb:


    So lift the connector off the mb just enough that you can expose the pins that connect to those green/white wires and short them. If it all fires up, you know you have to replace the switch. Cheap and easy.

    Good luck with all of it, and stay healthy.
    Davdi and Madasa like this.
  17. Madasa

    VIP Member Thread Starter

    All Right. Thank you @rootabaga :)
    rootabaga likes this.
  18. Madasa

    VIP Member Thread Starter

    The Motherboard and video card look quite new so I wouldn't see a trace of any faulty capacitors etc.

    I have seen those power connectors off of photos I took last night (having moved the pc to another room, ok the other room) so I may tinker with those again this evening - but the front switch is still encased despite levering off a black plastic front panel and I don't see a screw access unless I was to disassemble everything from the inside - but I imagine those labelled connectors solve that anyhow.

    Don't spend any more time on this for me, thank you - I'm good.

    I hope the info kindly offered may assist another person also, who may benefit as well from a similar upcoming mental health assessment to mine. :)

    I may either:
    successfully get it running it myself soon (I'll post it here, but don't buy the popcorn yet)

    get it to a repair store on foot or with opportune vehicle access (it's a heavy bugger)

    ... or sell it to a museum.

    Emmylou, Linda, Van the Man, John Deutchendorf and the others will have to vie for my attention later. Things are looking slightly better on the income front anyhoo.

    Screenshot_20200922-091205.png IMG_20200921_181830605~2.jpg
    #17 Madasa, Sep 22, 2020
    Last edited: Sep 22, 2020

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