Am I missing something? (hardware related)



  • Okay, so Saturday evening my PC simply ... died. As in: It behaved as if I had simply pulled the power plug. No magic smoke, no sparks, simply dark (was playing Witcher III at the time).

    Pressing the power button repeatedly yielded no results (yeah, I know, only a fool...). Only signs of life: The standby LED on the motherboard and a white LED on my new Geforce 970.

    Since I had run into power supply issues before (three times, to be exact. One of those PSUs I dubbed Mjölnir because it threw lightning out the back), I assumed this to be the culprit and set out to buy another one.

    Replaced the old PSU with the new one - no dice. Still no reaction other than the two LEDs.

    Hmmh, what if it's the graphics card? I still had my old one lying around - put that one in, and presto! The PC booted. Alright, another trip to the vendor, this time with the new card in tow. Got it replaced without any fuss (it's only 2 weeks old and thus falls under DOA rules at this shop).

    Back we go aaaaaaand... nothing. Damn it! Old card also doesn't change anything anymore.

    Reduced the whole setup to the bare minimum (i.e. the minimum requirements for RAM, graphics card and that's it). Nothing.

    So now I'm thinking it's the motherboard - already ordered a new one. But I'm asking here if I missed a step I could also try?

    But remember: It doesn't turn on at all. Thus no POST codes, no beeps, no nuthin'.


  • Winner of the 2016 Presidential Election

    I know this sounds stupid but have you tried changing your BIOS battery? I had a computer who loved depleting those. And replacing them is like 5 bucks. So it's worth a shot.

    Filed Under: Not promising anything, though



  • I've run across computers with a depleted BIOS battery before - those did still boot. They just lost the BIOS settings every time, resetting them to default values.


  • Winner of the 2016 Presidential Election

    I thought so as well until I had a certain computer that had some fun with them.That thing was probably TRWTF and I was young and foolish.

    Filed Under: Then again, your new motherboard probably has a new battery so all is well :D



  • I'll take the cheaper route and put a voltmeter on the battery tomorrow.


  • 🚽 Regular

    +1 on this. I've seen a computer not attempt to start with a low BIOS battery. Wouldn't have believed it otherwise.



  • @Rhywden said:

    Back we go aaaaaaand... nothing. Damn it! Old card also doesn't change anything anymore.

    Try a different power outlet.


  • Winner of the 2016 Presidential Election

    I hope you already have a voltmeter ready... otherwise I think the new battery is cheaper!

    @Cursorkeys said:

    +1 on this

    Filed Under: Yay, I am not the only one!



  • Tried that. That's not it.
    @Kuro said:

    I hope you already have a voltmeter ready... otherwise I think the new battery is cheaper!

    Got about thirty of them at my school. :)


  • 🚽 Regular

    Possibly not helpful in this case but a useful tip for trying to diagnose a dead motherboard is to remove all expansion cards and the RAM. If it and the processor are still on speaking terms you'll get a bleep code for memory controller failure.



  • You only get bleeps / POST codes if it actually powers up, though.


  • 🚽 Regular

    Sure, but it elimates the RAM as well and I have had a board appear 'dead' like that from faulty RAM (G.Skill crap)



  • Hm.

    You're 100% sure your PSU has the wattage to run that GPU? And when they put the new one in, they plugged-in the GPU's power connector, right?

    It sounds to me for all the world like your GPU isn't getting the juice it needs. Which is why I thought maybe the outlet was faulty and not giving your computer all the juice.



  • The old one was 530 W, the new one is 600 W (because I thought of that as well). That should be more than ample amperage on the 12 V bus. No cheap noname stuff either (beQuiet was the 1st one, Thermaltake the 2nd)

    Granted, there are 6 SATA devices (mixture of SSDs, HDs and a BluRay drive).



  • But when you downgrade video cards, poof, it boots up. Do you have access to a beefier PSU?

    I think my machine's running an 850.



  • No, it booted up once. Doesn't do that anymore.


  • Discourse touched me in a no-no place

    @Rhywden said:

    You only get bleeps / POST codes if it actually powers up, though.

    I had an HP laptop that wouldn't power up--all it would do was flash the LEDs in a pattern that I discovered meant "dead CPU".



  • Wait, did you put the old card in a second time? After it came back from the shop?



  • @blakeyrat said:

    Wait, did you put the old card in a second time? After it came back from the shop?

    No, went like this:

    Old card in -> PC boots up -> New card assumed faulty
    New card exchanged for even newer card -> installed, still doesn't boot
    Old card in -> PC doesn't boot anymore



  • @FrostCat said:

    I had an HP laptop that wouldn't power up--all it would do was flash the LEDs in a pattern that I discovered meant "dead CPU".

    According to the manual, there is indeed a 2nd LED which is supposed to blink akin to a Morse pattern if something is wrong. This LED is dark,though.



  • There's a slight chance that your power button has flaked out. You can test this by shorting 2 pins on the 20/24 pin power connector. IIRC it's the black and green pins, but please check first. I had to do this to troubleshoot an issue I had recently.



  • @Rhywden said:

    i.e. the minimum requirements for RAM, graphics card

    Have you tried without the graphics card? Do you have any integrated graphics? Even if not, it might still bleep.

    My bet is on the motherboard, though.



  • The CPU has integrated graphics, the motherboard doesn't have the connectors, though - a consequence of my (short) adventure with overclocking, at the time the unlocked motherboards didn't have that feature.



  • @blakeyrat said:

    Wait, did you put the old card in a second time? After it came back from the shop?

    Could be something is killing the PSU either aggressively (Device: "gimme infinite Amps" PSU: "Don't you mean W.... 💥 ") or passively (Device: "gimme 20A" PSU: "Whoa! hold on there, I've only got 5.... 😡 Right! Everyone! I Don't talk to me, cos I aint gonna answer, until he goes away).

    Had a USB device like that once. Not many ppl realise just what a drain on the PSU (which is a sensitive and cautious beast) they are. And that's after you get random issuses with the CPU / Memory cos the PSU giving 550 of it's 600W, the theres like a few hundred mV of noise on some of the critical voltages.

    If it can be removed, remove it. Give the mother board a good shake to remove any little bits of conductive crap, and a going over with a MKI eyeball looking little brown / black discolouration's (with texture or not) on the components.

    Yes you do need the CPU to be alive and sane for the thing to work, bit of a catch-22 that. But there is a "start up" voltage (which sometimes gets the arse blown out of it) and logic - otherwise collectively known as POST. You can use google to .... no, wait!. You can't

    Something is working 'cos you got LED's illuminating the path to.... where ever.

    Or you could just get a new MB. And then play Russian Roulette with it as you put stuff back in :devil:



  • I dare say that the standby LED simply means that the 5 V rail works. It's just that the 12 V won't engage.



  • Test the cables between the PSU and the motherboard? (particularly the 12V, or outright change that one)



  • I did replace the whole PSU...



  • forgot that...



  • Ok that third step was missing from your first narrative.

    I dunno then.



  • Me too. I had a machine like that just the other day.



  • I'd put a scope on the 12V rail and then try to power the board up with a CPU and perhaps 1 stick of known good RAM, no graphics board or other expansion boards -- see if something is causing the supply to trip out under load. If it powers up then, I'd check with a cheap graphics card at that point, as it smells like something is causing graphics cards to selfdestruct...



  • @Rhywden said:

    According to the manual, there is indeed a 2nd LED which is supposed to blink akin to a Morse pattern if something is wrong. This LED is dark,though.

    I've had an Asus motherboard actually telling me "CPU test failed", so plug speakers, you never know.



  • @TimeBandit said:

    I've had an Asus motherboard actually telling me "CPU test failed", so plug speakers, you never know.

    Yeah, but for that it'd still have to turn on, at least.

    Anyway, the matter is resolved. New motherboard and CPU are now running along nicely. I wanted to wait until the next generation of Intel chips but, well, now's as good as any time I guess...


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