Computer Woes

Factual Questions
1

This is actually a set of questions; wasn’t sure if it properly belongs in GQ or IMHO, but I’ll get typing and let the mods sort it out.

My computer suddenly ceased to function on Saturday. I had sat down, was moving the mouse to bring up a browser to check my email, and poof. The machine suddenly powered off. No bluescreen, nothing, just poof.

Attempts at resuscitation proved futile - it would not boot after a cooling off period, even after I vacuumed the heatsink/fan on the CPU (last time something similar happened, it was an overheating issue). The best it could muster was a flicker of power when the power button was pressed - the CPU fan would twitch, the case lights flicker, and then nothing.

My guess is currently that the power supply is having an issue, but I thought I’d ask the experts. The MB lights are on. The Power Supply is, clearly, supplying some power, and the motherboard hasn’t become nonfunctional. But either one of them could have a fault that’s keeping it from booting, I suppose.

So here are my questions -
Has anyone ever run into a similar issue, and what was it caused by?
Is there an easy way to test a PSU with, like, a voltmeter? I guess I don’t know which connector on the plugs would be grounds for all the various leads…

My boss at work suggested that I try re-seating the memory, as he once had a memory module shake itself loose and cause a similar issue, despite the security clips, so I may give that a shot later. I really am hoping it’s that, or the PSU - because if it’s the motherboard, that’s not a repair I feel comfortable doing myself, and I’m not ready to buy a new PC until Windows 10 is out…

2

either dead power supply or dead motherboard. the lights that are on probably mean the power supply is still supplying the 5 volt standby power, but nothing else.

3

You can buy a PSU tester. But if you have a volt meter, you can also just read some articles online to see which pins to test and runs the tests yourself.

It could be memory, I’ve seen that happen. You can pull it out, make sure the pins are clean and reseat it. But if you haven’t been in there messing with it recently, it’s a long shot. It doesn’t typically unseat itself. If you’re going to check that, It’d probably also try just taking the RAM out and powering it up, maybe also trying each stick by itself. Just to rule out one of them going bad.

I assume you would haven mentioned it, but did it beep? Are any of the fans running?
Something you might want to do is to just run up to Best Buy, buy a new (comparable), PSU and drop it in. If it works, great, if not, return it.

4

memory being out still might yield a beep or some screen activity before stopping at boot up.

to test a power supply you need to have a point where voltage is fed back to the power supply. even testing just for voltage doesn’t mean the supply is good. what and how to test depends on what actual supply you have.

connections or components in either the power supply or the motherboard could fail instantly.

a good step is to carefully unplug and replug, one at a time, power supply connectors to the mother board.

often, because it has become lower cost and is nonreparable, buying a replacement power supply at a store that takes returns easily is indeed a good strategy.

5

No beep codes. I get less than a second of fan movement and case lights when I attempt to power it on, then it’s off again.

Are power supplies all standard sized? That was my main concern about just buying a replacement. For the record, it’s a 550W Velocity Micro-branded PSU from 2010.

6

more or less, though the higher output ones (750-1000 watts) may be physically larger.

7

you need to match a replacement with what you have.

you need 550W (slightly more is OK without costing much more) which is common.

you need to match the number of connectors and number of pins in those connectors that you have in use. motherboards besides the main power connector (with the correct number of pins) also has additional connectors needed by your system.

there are a number of variations for current and past technologies.

8

Part of the “more or less” is that you should make sure the new one has the appropriate outputs and connectors for all the components you are going to plug it into. It probably will, particularly if there’s nothing particularly unusual about your system, but it doesn’t hurt to make sure.

If you want to keep it for a while, buy a good quality one, and I’d buy a modular design. That keeps you from having to wrestle with octopus tentacles that you don’t need.

9

Well, I popped onto Amazon and ordered a 600W Corsair PSU that seems to have the connectors I need. Hopefully, it’ll fit the case - I suppose I can return it if it doesn’t meet my needs.

It’ll arrive Wednesday and I’ll hook it up, and pray to the silicon gods that it works, because the motherboard alternative is far more expensive, any way you slice it.

Edit to Add : I like the idea of the modular PSUs, but they seem to cost roughly twice as much as the standard kind.

10

The new PSU should fit just fine in your current case. I’ve had lots of luck with Corsair, so I’d say you made a good choice there. If the problem isn’t the power supply I’d guess you have a bad temperature sensor somewhere in the system causing an immediate thermal shutdown; but like others have said the power supply seems like the best place to start.

11

yeah Corsair is a top brand that i’ve used too.

the mounting and overall sizes have become a standard. so you should be good. it might take a certain wiggle to get them in but they fit.

12

I’d say it is unlikely to be the PSU - that second of “kick” is the power supply starting, then not getting a “Power Good” signal back from the motherboard, and shutting back down.

13

Well, I’m hoping you’re wrong, for obvious reasons! :slight_smile: While I expect I could buy a new motherboard, I do not trust myself to do that kind of installation safely, so that would mean finding a pro, and more delays and headaches.

14

It’s tedious, but not that difficult, as long as you get the right form factor, one that works with your processor/cards/memory etc. But at that point you’re almost better off just getting a new computer. What if it’s not the mobo?

You mentioned in the OP not getting a new computer until Win 10 is out, but when I was looking at computers a few months ago (ended up not getting one), I thought a lot of the Windows 8 computers came with a free upgrade to 10. At least that was the case for laptops.

15

I’ve seen this before, and the problem was ultimately mechanical. (In the sense that it was a “mechanical” fix, not replacing electronics.)

It was a short between the motherboard and the case ground, caused by a loose screw (literally). The PSU would fire up and then very quickly shut down as overcurrent protection triggered.

I solved it after exhausting all the usual electronics troubleshooting, by disassembling the PC down to a mainboard in my hand and an empty PC case… with this stupid out-of-place screw rattling around in the case.

YMMV. Something to think about before replacing the MB.

16

the “PWR_OK” signal doesn’t come from the motherboard. The power supply asserts that line (brings it up to +5 volts) when it stabilizes, signaling the motherboard that it’s safe to begin boot-up.

17

I’ve had the case opened and turned every which way, so I’m sure there are no screws actually completely detached rattling around in there. I had to remove both sides and the front and the top to actually get the last arm of power supply cable out, and the thing was overdue for a dusting anyway. But I appreciate the input!

[QUOTE=Joey P]
It’s tedious, but not that difficult, as long as you get the right form factor, one that works with your processor/cards/memory etc. But at that point you’re almost better off just getting a new computer. What if it’s not the mobo?

You mentioned in the OP not getting a new computer until Win 10 is out, but when I was looking at computers a few months ago (ended up not getting one), I thought a lot of the Windows 8 computers came with a free upgrade to 10. At least that was the case for laptops.

[/QUOTE]

It’s not the difficulty, per se, that I worry about, so much as damaging the thing (via physical clumsiness, static electricity, or what-have-you). I’ve swapped drives, video cards, memory, PSUs - but never a MB or CPU.

And I was just reading about the free upgrade to 10, actually, when I was trying to find some idea of a firm release date for it. So that’s a thought, if it becomes necessary…

18

Confirmed : Power Supply. Installed the Corsair, it’s back up and running like a champ.

19

Brilliant! Glad to see the problem fixed!