Repair, upgrade or new system from scratch

  • gamingdave 4 Sep 2013 16:18:35 4,725 posts
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    I bought a computer in December 2009 which has recently stopped working. I am not sure if it is the motherboard or the power supply, but it refuses to switch on. There is a light coming on the motherboard but it doesn't even attempt to spin up the fans. I have tried a few things like removing the graphics card and swapping round the memory but it refuses to boot.

    Firstly, anyone got any tips for trying to diagnose if it's the power supply or the motherboard?

    It's obviously a little dated now, comprising of: Asus P7P55D Pro, i5-750 (overclocked by yoyotech) and an ATI 5850. There is a Corsair TX 750W as the power supply and then a BR drive, 4GB memory and a WD 750GB.

    Previous to it failing I was planning on upgrading it with an SSD, new graphics card, and possibly putting it in a new (quieter) case.

    My problem at the moment is I don't know what is working currently and so if I should be looking to repair and upgrade, or start from scratch with it all.

    Obviously being the first release of the i5 I am expecting the newer chips to have substantial improvements but I don't really know the ins and outs for gaming. The motherboard is not suitable for any of the newer chips at all. How much does a CPU do in modern games?

    If I was to get it working in it's current configuration and swapped the 5850 for a 7970 or similar would the processor/mb combination be a bottleneck at all?

    Tempted to build a whole new system, but if I can save money reusing parts I already have then I'm not just going to throw money away.

    Any and all advice greatly appreciated.
  • Deleted user 4 September 2013 17:38:06

    I know this is an obvious thing that won't be the problem, but check you haven't put the system into hibernation/standby. Holding down the power switch for 5-10secs and pressing down gain should rule that out, or using the keyboard shortcuts for standby/hibernation would toggle out of that mode.

    The light on the board rules out a faulty PSU(in 99% of situations).

    Next find the motherboard bios reset. On new expensive x79/z77 asus boards it is doable by an external switch, but typically this is a motherboard jumper(two metal pins and a cap) that you put across the pins(to close circuit), turn the system on; it beeps to reset, you turn it off and then uncap the pins(open cicuit) and restart the system with a reset bios. This will be labelled on the motherboard and in the motherboard manual.

    If the system fails to boot with a reset bios then you probably have a faulty video card; because if it is memory or the CPU or the HDD or the DVD-rw the bios should still function. If you have an on motherboard video out try that after removing the GPU(with a reset bios).
  • gamingdave 4 Sep 2013 17:47:04 4,725 posts
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    Cheers for the reply vizzini.

    Definitely not in hib/standby.

    Not seeing how I could do a bios reset, as there is no way to turn it on to trigger that.

    I have tried without the graphics card in at all, and it was exactly the same.
  • MrTomFTW Best Moderator, 2016 4 Sep 2013 17:55:00 47,493 posts
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    gamingdave wrote:
    Not seeing how I could do a bios reset, as there is no way to turn it on to trigger that.
    If you're not shy with hardware you could remove the battery...
  • Deleted user 4 September 2013 17:55:35

    Power on switches on all modern PCs are soft switches, they aren't like a modal light switch, more a variable resistor with the bios monitoring for conditions to be met. When the bios jumper is closing the circuit the front power switch on the PC press should be intercepted by the bios to reset and override all the overclocked settings. Then you open circuit the jumper and the bios then reads the switch on as a normal attempt at starting the system.

    If this doesn't work then open the front panel on the Pc case and check that the switch is actually seated correctly. If the switch has come loose, your press on the button might not even be doing anything.
  • gamingdave 4 Sep 2013 18:04:49 4,725 posts
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    MrTomFTW, are you talking about the battery that can be seen in the middle of this pic:

    As you can tell i'm not the most knowledgeable about these things, but not shy of having a go.

    vizzini, I have tried manually shorting the two pins the switch connects to on the MB with a screwdriver as I thought the switch may be the issue, but this didn't actually do anything. Is this what your suggesting?
  • superdelphinus 4 Sep 2013 18:07:56 9,791 posts
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    Lick it
  • MrTomFTW Best Moderator, 2016 4 Sep 2013 18:18:00 47,493 posts
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    gamingdave wrote:
    MrTomFTW, are you talking about the battery that can be seen in the middle of this pic:
    Yep that's the one. Pop it out, give it 60 seconds (probably doesn't even need that) then reseat it. That should reset the BIOS to factory settings.

    Also viz is right about checking the power is connected to the mother board correctly.
  • TheSaint 4 Sep 2013 18:19:27 17,702 posts
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    I would start by checking the white connectors in the bottom left area of the pic you posted. This is where the connection from the case power button meets the motherboard and would be my first guess at the issue.

    If you don't have the motherboard manual download it from the Asus website to check everything looks right.

    Edit: bottom left not right.

    Edited by TheSaint at 18:20:08 04-09-2013
  • gamingdave 4 Sep 2013 18:32:54 4,725 posts
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    TheSaint, I have checked that and it was connected properly. I tried jumping it with a screwdriver and nothing happened. Is that the correct way to test it?

    MrTomFTW, I will try that later tonight and see what happens.

    I have an old shuttle PC that I think works. I'm going to test that too and see if it still works. If it does I assume I could try the PSU from that easily enough with just the MB having a processor, memory and fans attached to at least see if it springs into life. And indeed, try the current PSU on the shuttle to see if it will power that up.
  • Deleted user 4 September 2013 18:39:58

    The blue jumper next to the CLRTC writing is the bios reset jumper according to the manual (page 42 in the english pdf)

    The information others are saying about checking all your power and switch connections is all top drawer. between checking connections and removing any overclock that might be hanging the board, we should be able to get your system to display something.
  • Fake_Blood 4 Sep 2013 19:08:16 8,533 posts
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    No bios setting is going to prevent your fans from spinning up.
    It's your power supply.
  • Deleted user 4 September 2013 20:47:44

    It is more likely that the front case switch has been push back into the case and isn't actually in contact with the plastic switch at the front that is being pressed. That or the cable block from the case is faulty or not seated in the motherboard correctly.

    PSU? In the old days yes PSU faulty if fans don't move, now with modern load bearing PSUs and motherboards that control every fan I wouldn't rule it out. If the bios overclocking settings are hanging the board it won't add a resistance load to the PSU and will cut the supply early to ensure all the components remain protected. Although it does seem odd that the motherboard wouldn't self fix incorrect settings on such a relatively new motherboard if it was an overclocking problem. I guess it depends of if those safety bios features were disabled as part of the overclock.
  • MMMarmite 4 Sep 2013 21:25:01 1,564 posts
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    Get a multimeter and test that sucker ;)

    Safety Notice: obviously if you have another motherboard try it on that as it would be safer. I don't normally agree with Vizzi but also try using the CLRTC jumper to clear the bios settings.

    Edited by MMMarmite at 21:27:47 04-09-2013
  • Frogofdoom 4 Sep 2013 21:31:18 7,915 posts
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    Its almost certainly your power supply, i have had countless psu's that have still lit the led on the motherboard despite being dead. Its probably got a blown capacitor or something on it.

    Try another one and im pretty sure you will get some life out of it.
  • gamingdave 4 Sep 2013 22:28:02 4,725 posts
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    I have now tried resetting the bios, using the jumper, but there is still no sign of life.

    I've had the front of the case and the power switch feels fine, but I have also tried just shorting the two pins on the connector for the pin.

    Yoyotech (who built it originally) have quoted 60 for a full diagnostic which won't incur any extra costs if it's a basic fix not requiring any replacement components. Considering how much it would cost me to get a new PSU to try, and my lack of knowledge to really try lots out (though you have all been helpful in your advice) I'm thinking it may be the simplest route.

    So this leads on to me second question. If was to need a new power supply, was planning a new graphics card and ssd, and also a new quieter case then thats basically everything bar the MB and processor. I could keep the memory though may up that too.

    How much impact does the processor have on PC gaming these days? Would I ideally want to be upgrading them as well to go with something like a 770 or 7950/7970?

    If thats the case then I may as well just get a whole new machine, then try and repair the current machine as cheaply as possible to either use somewhere else, or sell to recoup costs toward the new one.
  • Deleted user 4 September 2013 22:41:44
    More than it it used to, but your i5 is probably still good enough for a lot of stuff. Stick with your upgrade plan and do the CPU/MB later.
  • FartPipe 4 Sep 2013 22:48:57 5,307 posts
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    Take your PSU to someone that can test it for you, I'm sure Maplin would oblige.
  • gamingdave 4 Sep 2013 23:01:48 4,725 posts
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    There is a local PC shop, not heard the best things about them, but I can pop in and see what they say.

    If I can stick to just a new PSU, SSD and graphics card I can keep the cost down to under 500 as opposed to more like 1000 for a full new machine. That's enough for the PS4 too so as long as the i5 isn't going to cause slowdown in any games then it does make sense.

    I only game at 1920p as it's either on the TV or projector, but I do want to turn settings all the way up, and if I am getting a new card I want it to last me a good few years.
  • TheBlackDog 4 Sep 2013 23:28:54 1,061 posts
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    @gamingdave I reckon that you'll be fine running that CPU and mobo combination (if they are working) for a good few years yet, especially if the overclock is set-up right towards the 4 Ghz mark. You will need a quality PSU though, especially for the more powerful GPU and to cope with the CPU overclock.

    I've got the same first gen i5 750 with a 7870 and my CPU isn't the bottleneck, and I believe the i5 750 would cope with something more like a 7950 or better.

    If it is the PSU thats faulty just make sure to replace it with something quality - obviously the watt rating of the PSU is important (750w would have been sufficient for what you had and are planning on upgrading), but equally important is how many amps your PSU is going to deliver on the 12v rail(s). My PSU is rated at 500w which is just on the limit for my CPU overclock and a slight GPU overclock, but when I put in the 7870 I notice I had to dial back the CPU overclock to get the GPU running stable even at its stock setting. Its probably to do with the fact that my PSU only provides 18A on each of the 2 rails, as opposed to a better quality PSU delivering a total of something like 50A (preferably on a single rail).

    TL;DR: the i5 750 is fine for gaming with a high level GPU, but get a really quality PSU if that is the problem and is being replaced (especially to cope with any overclocking).
  • Deleted user 4 September 2013 23:30:35

    Did you get to swap the reset and power switches around (page 58 of the manual)? This will rule out a faulty power switch on the case as shorting the pins with a screw driver isn't really the greatest test and that is still quite an impressive PSU that shouldn't be failing while powering such a small amount of stuff.

    Re-upgrade; personally I think doing a full upgrade is the wrong time for you and instead a cheap fix and minimal upgrade(SSD/GPU) until we see how the new hybrid consoles work out for PC game development is better. That 60 for diagnostics might be better spent on new parts.
  • gamingdave 4 Sep 2013 23:42:56 4,725 posts
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    Yep, tried swapping the reset and power switches over, no change.

    Thanks for your post @TheBlackDog, very helpful
  • Deleted user 5 September 2013 00:00:25
    Also, rather than getting a new case, why not get a new CPU cooler and pay a little extra for one of those quiet GPU jobbies?
  • gamingdave 5 Sep 2013 10:11:30 4,725 posts
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    I already have a Coolmaster Hyper 212+ cooler in the current machine, and its certainly not loud. The case, an Antec 300, is fairly quiet, but I was thinking something like the Fractal R4 would bring the noise right down.
  • Deleted user 5 September 2013 14:25:22

    It occurred to me today that I didn't ask you two really basic questions about your PC setup yesterday that have a 0.00000001% of being the source of your problem and thought I'd throw them in for good measure.

    Is your PC PSU cable going directly to its own mains power socket on the wall? And have you made sure that only the monitor vga/hdmi, keyboard, mouse, are connected to the PC(eg no dongles in usb ports)?

    The reason I ask, is that PSUs can play up if they don't have enough dedicated supply from the wall (instead of going through extensions with surge protection) and if you have anything like a usb hub (in the monitor or keyboard) and a live device like an external powered HDD connected the PSU will not drive power under certain circumstances (as I experience myself 4years back).

    Also if you have had the GPU out, just make sure you have reattached the GPU power correctly. Systems have been known to refuse to boot to protect the motherboard from underpowering a GPU.

    If your motherboard and PSU can be connected using either ATX/EATX power instead of the other option, you might want to try the other "valid" configuration just in case one of the PSU cables you are using has gone faulty. I doubt this is an available option for the mb/PSU combo; but again, thought it was worth mentioning.

    Edited by vizzini at 14:32:40 05-09-2013
  • gamingdave 5 Sep 2013 15:15:51 4,725 posts
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    PSU is direct into mains, nothing else. I have tried booting with nothing external connected at all as well.

    GPU is definitely reattached correctly, pins/connectors all firm and all the way in.

    My old shuttle does work, though damn noisy, but the power supply is integrated and so not easily removed. I may be able to get the cables to stretch though so will try just the two main cables to the board with everything else off and see what happens.
  • Fake_Blood 5 Sep 2013 17:14:02 8,533 posts
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    You may want to connect the two chassis and remove the mains cable from the busted pc there dave.
    Power supplies fail more easily than switches vizzini.
    Even the chinese have figured out how to make two bits of metal make contact reliably.
  • gamingdave 6 Nov 2013 21:58:34 4,725 posts
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    Finally managed to borrow a decent PSU from a mate to test. Whilst it didn't have the right connectors for the graphics card, and there is no onboard graphics output to test with, it did power up the PC. The fans all whirred into life, and I could hear it starting up the HD.

    Went to get a returns form for the PSU from corsair and the first page I came to on their site was regarding a way to test it with a paperclip and a fan. Tried it, and it confirmed the unit had failed. Should have checked that 3 months ago! Anyway, it's now on it's way back to corsair under warranty, but at a cost of 30 as it has to go to the Netherlands.

    Looked at some comparisons on and it looks like as long as the CPU is overclocked I am not going to get much of a boost from a new CPU at this point. So it looks like a new card, probably a R9 280X and an SSD will go into it, and use the leftover money for one of the next gen consoles (probably PS4).
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