dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
2184
share rss forum feed


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12

Troubleshooting a PSU

So a non-enthusiast (very basic user) friend of mine is having trouble with his desktop. He's given it to me for a couple weeks to see what I can do with it, as well as install a few upgrades for him (an SSD, a couple of silent case fans).

He said it will occasionally shut down on him, especially if he's been using it for a couple hours. My first thought is heat, so I'll be dust-busting it out and then watching the temps as I stress-test it.

My second concern is the PSU. I am not an electrical engineer, so I am wondering if those of you out there who are more knowledgeable of electricity and power supplies can give me some pointers on how to check to the PSU to see if it is going bad or supplying dirty power.

All I know so far is that it's a Kingwin MK-750w. I should be getting it from him tonight and will know more a little later on.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


Freddy
Premium
join:2005-05-17
Arlington, VA
kudos:2
Kris,

I used one of these to test my power supply. It showed the 5 volt line was out:

»www.outletpc.com/ep1827.html?gcl···odO1NqMQ

It worked for me, and it's cheap, too.

Freddy

bbear2
Premium
join:2003-10-06
94045
kudos:5
reply to Krisnatharok
You certainly can purchase that PS tester and go that route. If you have a volt meter and a paper clip and are comfortable around the wires, you could bench test the PS outside of the PC. However, if the system is running for hours on end, I would go in the direction you started to and look at heat issues. When you are dusting it out, don't forget to dust out the PS and internal fans too.

You can also feel the exhaust air coming out. It should be warm, not hot, and at a steady force, not weak. You can also monitor this when it first starts and then again after several hours.

Also observe the CPU fan and make sure that's working properly - e.g. no strange noises and steady speeds, not jerky.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
Thanks for the replies--I think I have a voltimeter I can break out as well.


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23
reply to Freddy
The biggest problem that I have with those PSU testers (like the one Freddy See Profile linked -- yes I have one, different brand though) is that they're misleading for troubleshooting complex problems. Let me explain:

These testers will tell you two things, and those alone:

1) If there's no voltage at all (some sort of short, broken pins, something blew up, etc.) to each individual voltage bit (3.3V, 5V, 12V),
2) What your voltages are when plugged into the PSU tester.

#1 is totally legitimate -- no beef there. It's #2 I have a problem with.

Remember: these testers are not in-line devices. Meaning, they do not sit between your PC and your PSU; you plug the PSU into the tester and look at an LCD and go "uh, yeah, okay". That's the analysis? Half-ass.

These devices in no way shape or form stress a PSU the same way a PC does. Consider voltage-wise what all goes on with a GPU hooked up, 4 hard disks, a motherboard, and possibly a 2x4 (or 1x8) ATX12V connector for a single or dual physical CPU system. Do you really think the voltages are going to be the same in that situation as when hooked to a little PSU tester?

If these testers were in-line they would be *super* useful. Imagine if one of your 12V lines dropped suddenly to 10.8V then ramped back up to 12V in the middle of the system being used. The device could maybe emit a tone/buzzer, or (what I'd love) keep some kind of log (maybe even offloaded to a serial or USB port so you could hook it up to a laptop/other system and log what the voltages are in real-time -- wow, imagine that, something we've done for years in the hardware monitoring world... ).

Take for example this exact situation of mine. One of those PSU testers wouldn't have been able to diagnose this; the 12V lines drove 12V no problem, except for very specific situations where they'd drop out, thus the problem I experienced. I was lucky to find what I did visually, otherwise I would have been replacing hardware piece by piece until the issue went away (and sometimes it took days before it recurred).

So when using one of those PSU testers, keep all of what I've said here in mind.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.


Archivis
Your Daddy
Premium
join:2001-11-26
Earth
kudos:19

1 recommendation

reply to Krisnatharok
In my experience, if a power supply unit goes out, it will not "work for a few hours" and crap out. Every time I've seen a computer do this is because of the processor getting too hot. One time, I saw that the heat stink/fan combo wasn't seated properly. Another time, The thermal compound had turned to powder from age.

Nothing else would cause this to happen. If a video card overheats, artifacts show up, the fan winds up loud and the machine can "stall", but a strict power-off is the CPU hitting a certain temperature threshold and the system shutting off as a result.
--
A government big enough to give you everything you want, is strong enough to take everything you have. -MLK


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
reply to koitsu
I hear what you're saying. I am hoping I can mimic my friend's problems by letting it run a stress-test for a couple hours and see if it flakes out on me.

I got the PC last night--I didn't have a chance to start it up, but I did poke around inside, and it has:

MSI micro ATX board
AMD 1055t CPU w/a lay-flat CPU heatsink/fan
Four sticks of two types of ram (guessing 8GB)
GeForce 500 series GPU (550 or 560)
2 HDDs
1 Optical drive
Kingwin MK-750 PSU
CM HAF 912 case

He dropped off a Vertex 3 120GB and a Hyper 212+ he said he wanted installed (no idea on the CPU cooler--I'm guessing an attempt at lowering temps) along with some money for misc. extra parts.

My plan of attack, which will probably have to wait until the weekend, is to sweep it out and do all the stability tests before I add anything, then add the SSD and new CPU cooler. His case also has no fans beyond the 240mm one in the front, so I might pick up a couple case fans for him to put on the top and side and create some positive pressure inside the case.

My biggest concern is the PSU. I hadn't even really heard of Kingwin before, and it appears that some of their higher end PSUs get good reviews (the Lazer Golds--ppl seem to like their 1000w and 1200w ones), but the one in question here--an MK-750--isn't even bronze certified and only costs $80 at MicroCenter. In fact, none of the MK series ("Superflower" in OEMs) have any efficiency certifications.

It's hard to find reviews on this model or the MK series (already checked JonnyGuru), so I'm hoping someone here could provide intelligent feedback about whether it's "good enough." If there's a specific test I'd need to run to make that decision, please let me know.

For my friend's build, I'm inclined to think that a 550w PSU is all he needs, but have not yet decided if I need to replace the current one.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


Dissembled

join:2008-01-23
Indianapolis, IN
reply to Archivis
said by Archivis:

In my experience, if a power supply unit goes out, it will not "work for a few hours" and crap out. Every time I've seen a computer do this is because of the processor getting too hot.

+1

I've had a fair share of PSU issues and if it's dead, it's dead. And if it's "going out", it produces symptoms similar to bad RAM with random BSODs.

My dollar is betting that if you give his rig a good cleaning and are replacing fans anyway (especially CPU), he should be good to go. And it sounds like he's getting a new heat sink too, so he'll get new silver.

Per your point, I'd invest in some good case fans before I messed with that PSU.


Archivis
Your Daddy
Premium
join:2001-11-26
Earth
kudos:19
reply to Krisnatharok
You're putting too much thought into the PSU. The problem lies with the CPU overheating most likely.

bbear2
Premium
join:2003-10-06
94045
kudos:5
reply to Krisnatharok
said by Krisnatharok:

...
My plan of attack, which will probably have to wait until the weekend, is to sweep it out and do all the stability tests before I add anything, then add the SSD and new CPU cooler. His case also has no fans beyond the 240mm one in the front, so I might pick up a couple case fans for him to put on the top and side and create some positive pressure inside the case.

If you really want to troubleshoot the problem and be certain of the fix, do NOT sweep it out first. The first thing you should do is not change anything and turn it one, run stress test or whatever and see if you can duplicate the problem. If you can, then commence with your cleaning, etc., and rerun your tests. If the problem can no longer be duplicated, then you have resolved it with your cleaning actions. If the problem cannot be duplicated, then you need to look elsewhere including something unique at his house.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
So I started pretty much the same way. Booted up, verified temps were in the OK range (CPU was 25 C for a 1055t, 560ti was 29 C), and started a one-hour LINPACK CPU test.

Three minutes after it started, CPU temps were at 59 C when the computer just shut down and wouldn't start back up. 59 C should not cause that type of behavior.

Here is the feedback I am getting from the PSU--this would indicate it is operating correctly, no?



I'm going to give it 5-10 minutes to cool off and see if it will boot back up. If not, I'll start swapping out components, starting with RAM, and see what fried.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


Archivis
Your Daddy
Premium
join:2001-11-26
Earth
kudos:19
Is there a blue screen or just a quick power off?


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
It just died.


Archivis
Your Daddy
Premium
join:2001-11-26
Earth
kudos:19
I'm too lazy to scroll up, but have you taken a look at the CPU? Not just the reported temps, but an actual look at the CPU? Repaste and reseat the thing.
--
A government big enough to give you everything you want, is strong enough to take everything you have. -MLK


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
said by Archivis:

I'm too lazy to scroll up, but have you taken a look at the CPU? Not just the reported temps, but an actual look at the CPU? Repaste and reseat the thing.

That's on the to-do list tonight. I wanted to test it for stability before I cleaned anything, but it's possible the CPU fan and heatsink are full of dust. I'll repaste and install the 212+ and see if it boots.

If it doesn't, I'll swap PSUs. If not, then I may have fried the mobo or CPU.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.

bbear2
Premium
join:2003-10-06
94045
kudos:5
reply to Krisnatharok
said by Krisnatharok:

It just died.

Has it been able to boot since?


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
It's dead, Jim.

Won't turn back on. A couple of tries had all the fans (case fans, CPU fan, GPU fans) start to turn a couple millimeters before stopping. Nothing will respond now.

On the to-do list tonight is re-seat the CPU, and pull out the PSU and test in another computer to ensure it still works.

I'm not a fan of the PSU to begin with, but the fact that I could get a reading off it (see pic above) while the computer refuses to boot up lends me to believe it's a CPU/mobo issue. I am really hoping re-seating the CPU takes care of it, but if not, I may need to look into replacing either the CPU, or motherboard, or both (which sucks because I have no other AM3 CPU/mobo to try them in).

Edit: I checked the mobo for burst or bulging capacitors and found none. That said, it's a low-budget MSI AM3 board and doesn't even have a debug screen on it.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.

bbear2
Premium
join:2003-10-06
94045
kudos:5
Easy things to try before re-seating CPU: Re-seat the PS connector to the MB, make sure the additional +12V plug is seated properly too.

Also try removing all unnecessary items (e.g. disks, I/O cards, extra memory, DVD drives), except minimum memory, and graphics card (if it does not have integrated graphics). Your goal is to reduce the PS draw to only that which is critical and also remove other potential unknowns. Don't forget to pull the data cables too from drives.

asdfdfdfdfdf
Premium
join:2012-05-09
kudos:3
The fact that the power supply tester showed it ok doesn't mean that much. Having fans spin but not much else can very well mean the power supply is shot. I would check with another psu before I would bother dismantling the cpu cooler.

asdfdfdfdfdf
Premium
join:2012-05-09
kudos:3
"The fact that the power supply tester showed it ok doesn't mean that much."

reason being there isn't a significant load on it.

techguy2012

join:2012-05-17
Mundelein, IL
reply to Krisnatharok
I thought some of the better power supply testers have wire wound resistors in them to "simulate" a load on the 12v and 5v lines.


norwegian
Premium
join:2005-02-15
Outback
reply to koitsu
said by koitsu:

These devices in no way shape or form stress a PSU the same way a PC does.

When trouble shooting anything beyond swap and fit, stress testing is the best way to analyze anything. Computers, cars, you name it. I'm no engineer but know from a vast source of "jack of all trades" knowledge. Yes the tool will tell you voltages, but will it tells amps, watts? I'm no sparkie either so I'm not sure if resistance and all other types of tests can be done?

Still, for the price, I'm thinking of investing in one. Love to be a valid user of a multi-meter but haven't had anyone show me, and electrical currents being what they are, unsure is not a safe practice.
--
The only thing necessary for the triumph of evil is for good men to do nothing - Edmund Burke



Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
The Killawatt can show voltage, amperage, watts, watt-hours, and at least one more thing. Unfortunately, it's on the outside end of the PSU (between the PSU and the wall), so I have no idea what type of power the PSU is delivering to the computer.

I ended up getting home from work really late last night and didn't get a chance to play around with it last night. I have a new PSU coming on Thursday but I may pull out one of my own to test it on earlier than that.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
reply to Krisnatharok
I just spoke with my friend. When he contracted with the local shop to build this computer in 2010, he specifically asked for a Corsair PSU because he "heard they were good" (yeah, yeah, I know, cut the guy some slack).

It seems the local shop willfully mislead him and put the crappy Kingwin MK in there. I'm giving him the burnt-out PSU when I get the replacement on Thursday and he's going to try and hold the shop's feet to the fire and get it replaced.

The PSU is technically still under warranty, but I don't know if Kingwin will honor the warranty given that it was sold as a pre-built computer.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


psafux
Premium,VIP
join:2005-11-10
kudos:2
said by Krisnatharok:

The PSU is technically still under warranty, but I don't know if Kingwin will honor the warranty given that it was sold as a pre-built computer.

Unless the mfg specifically has an agreement with the merchant to transfer warranties to the end user the warranty will extend to the business and it would be up to them to handle the paperwork / RMA process.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
Exactly why I hate buying--or recommending that others buy--pre-built computers. You end up losing a longer manufacturer's warranty for a shorter, more expensive 1-year warranty that involves giving up the entire computer (you'd have to give up or RMA the entire rig to the vendor).

Given what I know about this computer store, I am predicting that he will be stiffed, so his recourse will likely be a nasty online review and a complaint with the BBB.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1
Reviews:
·Frontier Communi..
reply to Krisnatharok
Power supply testers will tell you if the PS is broken outright, but won't tell you anything about how it might behave under load.

To troubleshoot a PS under load, one needs a voltmeter (suitable ones can be had under $10) with proper probes, and/or some straightened paper clips for connection. Measuring voltage should uncover the majority of likely problems.

To measure noise, one would need either a scope, or perhaps a sensitive AC voltmeter.
--
Wacky Races 2012!

Mister_E

join:2004-04-02
Etobicoke, ON
Reviews:
·Bell Sympatico
reply to Krisnatharok
Have you tried resetting the CMOS? I've come across quite a few occasions where a system wouldn't boot (and it's not PSU related) and a CMOS reset fixed the issue.

Also, since the system is AM3 this may be related - I had the annoying experience with my previous EVGA Socket 939 system (Athlon X2) that would consistently report an overheating issue despite the heatsink being cool to the touch - reseated/reapplied TIM a couple of times without any change - looked like the sensor was just reading incorrectly...until I checked the heatsink retention bracket...EVGA (or I should say, Jetway) had cheaped out and used plastic push pins for the retention system which, while working, no longer provided a good cpu to heatsink mating (even though the heatsink also still appeared to be well installed when 'locked' in)..I replaced the retention with a bolted version (pulled from a 'cheaper' Asus 939 board) and the problem was solved (you can find retention brackets on ebay, etc.). System still running well as my daughters PC (after some bad caps were replaced as well).

So, once you sort the no-boot issue, if you're seeing an overheating issue, double check the retention system used on the MSI board...


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
The mobo this guy put in is a $50 POS: »www.msi.com/product/mb/785GM-P45.html

This board is so cheap it doesn't even have a CMOS reset button. It has a CMOS reset jumper: »download2.msi.com/files/download···v2.0.zip (page 2-18)

I'll admit I've had less time than I like to troubleshoot this system, but the new PSU showed up last night and verified that the problems run beyond just the PSU. I haven't tried the current one in another desktop, so that is on the menu for tonight, as well as disconnecting almost everything to try and get the mobo to boot. I'll also be trying a CPU re-seat.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.


Krisnatharok
Caveat Emptor
Premium
join:2009-02-11
Earth Orbit
kudos:12
Took apart the computer, unplugged all the HDDs/ODDs, reseated the CPU, reset the CMOS via jumper, put in verified good RAM, put in the new PSU--no dice. Thing is still very dead.

I'm guessing it's either a bad power button (this mobo is so cheap there is no on/off or reset switch on it) or a blown mobo. My friend's asked me to order a new mobo for him regardless (guessing it was the 785G he got with one PCIe 2.0 slot when he asked the builder for SLI capability up front), so a 990X is on it's way.

On the off-chance that the power button on the HAF-912 was blown too, does anyone have an easy way to jump-start a mobo by shorting the right leads? I linked the mobo manual, just not sure on the execution, since electricity and I don't normally mix sans protection.
--
If we lose this freedom of ours, history will record with the greatest astonishment, those who had the most to lose, did the least to prevent its happening.