$7 tester showing +12 stays on after shutdown

[mikeford]

I ordered a cheap $7 shipped tester from Meritline http://www.meritline.com/pc-pins-power-supply-tester-771---p-34538.aspx , and it arrived yesterday from Singapore. Looks the same as many of the other testers I saw priced from $10 to $20, slightly smaller than a 3x5 card it has all the basic connectors, floppy, drive, sata, 4, 6, 8, 20, and 24 pin, with 7 leds on one end for all the PS voltages, and 3 leds on the other end for 3.3, 5, and 12v on the drive connections.

All I have tested so far is plugging in a floppy power plug, which lights the 5 and 12v leds.

After shutdown the 12v stays lit, does that sound like bad PS?

I plan to get a 24pin PS Y cable so I can have the tester plugged in while the PS is plugged into the motherboard (guessing I need to remove the wire to the tester that turns the PS on for this).

 

[SparkyJJO]

Do fans and things keep running when the PSU is "off" ? Does the power supply fan stop spinning?

If no, then the tester is wonky.

 

[Meghan54]

I wonder why it "tests" for the -5V lead since that lead was discontinued from power supplies years ago.

Don't know what leaving it plugged in when powering your system will accomplish. All it tells you is yes/no for the different rails.....if you really want to check your power supply and what it's doing when powering your computer, go buy a DMM...they're not expensive.

 

[jonnyGURU]

Looks the same as many of the other testers I saw priced from $10 to $20....

Not to me. It's shorter and the configuration is different.

The Coolmax, Ultra, etc. unit is manufactured by Youngyear. This one doesn't look like a Youngyear.

 

[ehume]

PSU's often stay on a bit, powering case fans and pus fan after the computer has signaled a soft off. I suspect this is to make sure hot things are cooled off a bit.

 

[mikeford]

Do fans and things keep running when the PSU is "off" ? Does the power supply fan stop spinning?

If no, then the tester is wonky.

CPU fan at least is still spinning when off, that was what started me wondering, then system started failing to boot. Hit the power button and either nothing would happen or system would beep after a second, but hitting reset and system would boot fine.

Regards the -5v, these testers get used on some OLD hardware, plus likely the design is a migrated one with circuits added to an older design and nothing removed.

 

[jonnyGURU]

Ok.. let's go this route... What kind of PSU is it?

 

[mikeford]

Yes, what it is does remove a lot of questions. I think I bought it at Fry's, but found a listing and reviews on Newegg, three egg review, but split between one's and five's.

Eagle Tech Cool Power ET-PSCP 500 500W ATX12V Power Supply
http://www.newegg.com/Product/Produc...82E16817193017

Mine has a QC sticker with 7/2008 marked, 1 year warranty expired, so I think I will just swap it out later today.

 

[SparkyJJO]

Yeah PSU isn't shutting off fully if the CPU fan is still running. The question is, is it the PSU's fault or the motherboard's fault? I've had both happen.

Given the PSU it is, I'd blame PSU first, and hope it didn't damage the motherboard.

 

[theAnimal]

Eagle Tech Cool Power ET-PSCP 500 500W ATX12V Power Supply

Wow, a whole 200W on 12V!

 

[jonnyGURU]

Seriously? That PSU is utter crap. That's one of those "when in doubt, just replace the crappiest component". In this case, it's the PSU.

 

[mikeford]

Digging through my pile of parts not yet used I find ....

A Power Ultra Edition 480 watts, dated 8/2005, no UPC on the box. 17amp on the +12v.

OTOH its new in the box.

YIPES, thought about putting this PS in my old W98 system with a bad PS, same brand and date already in it. OTOH did work fine for a few years....

 

[jonnyGURU]

OMG! That PSU is even worse. It's like you're rooting through my trash can.

Ok.. You can at least test the A-Power and see if you can duplicate the always-on +12V. If that problem goes away, you at least know the Eagle Tech is done for.

 

[Rifter]

dude seriously just go out and buy a corsair 400CX for $30 after rebate, its cheap and a rock solid unit.

http://www.newegg.com/Product/Produc...82E16817139008

 

[mikeford]

dude seriously just go out and buy a corsair 400CX for $30 after rebate, its cheap and a rock solid unit.

http://www.newegg.com/Product/Produc...82E16817139008

As soon as it goes back on sale (like it was for two weeks prior to system getting wonky) I am all over one of the Corsairs.

I've got an Antec 620 sitting here, and something else buried in another part of office, must be good as the fan grill is gold plated, but we have a LOT of computers around the house that need new PS, and all the good ones are spoken for. Its just really odd to have so many systems with bad PS, but a six months or so ago we had a series of black and brown outs. Normally we never have troubles due to all underground lines in our area, and proximity to a substation, but we were on and off for several days during some repair work.

Found my third old, new in the box PS, its chrome not gold, so maybe not as good as I hoped. Reviews suggest its a good for low power rigs, which suits either of the systems I have in mind.
Linkworld LPJ12-400W (PSWB-400) 400W ATX Polished Chrome Power Supply
http://www.newegg.com/Product/Product.aspx?Item=N82E16817165007

Will post again tomorrow after swapping some stuff around.

 

[Meghan54]

I've got an Antec 620 sitting here, and something else buried in another part of office, must be good as the fan grill is gold plated, but we have a LOT of computers around the house that need new PS, and all the good ones are spoken for. Its just really odd to have so many systems with bad PS, but a six months or so ago we had a series of black and brown outs.

Given the quality of the last two power supplies you've listed, the Eagle Tech and Ultra, it's no surprise that you've started having failures. It's just like saying you cannot believe your Yugos are crapping out on the side of the road. Buy cheap and that's what you get.

BTW....I'm hoping your comment that a power supply "must be good as the fan grill is gold plated" is simply tongue-in-cheek, right?

 

[mikeford]

I tend to build low power set ups, and honestly those are the FIRST power supplies I have purchased by themselves. I've had good results using the ps shipped with the cheap cases I use. Talking CHEAP cases too, ala $30 shipped with PS, combined with Fry's combo's, and cheap memory. I don't over clock, don't run high power video cards, don't run a lot of drives, etc etc., so yes its a bit odd that after many years several systems are down with similar issues in a short time frame (six months or so).

 

[jonnyGURU]

Given the quality of the last two power supplies you've listed, the Eagle Tech and Ultra....

The second PSU wasn't even an Ultra. It's an A-Power Ultra Edition. Even an Ultra would be a step up.

 

[jonnyGURU]

...so yes its a bit odd that after many years several systems are down with similar issues in a short time frame (six months or so).

A number of systems are down with similar issues within a short time frame? These cheap power supplies don't die when you're building the PC's. They die six months down the road or kill all your other components. It doesn't matter how much power you're pushing.

Back when I was lead tech @ TCWO, we had a limit on how cheap our chassis w/ power supplies could be. Because of this, we had one customer that would buy everything BUT the chassis from us. The chassis he bought was $20 and had a cheap Leadman built PSU in it. After six months to a year, he would bring every system back to us.

Every motherboard had either buldging caps or fried VR's. He was the only customer to return this particular board with these symptoms. My first thought was the power supply since it was the one part he didn't buy from us. Of course, he took offense to this since he thought I was telling him this because it was the only part not bought from us. I tested his PSU and sure enough, it "worked", but even with only a 100W load on it there was 200mV of ripple. This basically slowly killed every component in it's path.

 

[ehume]

I get the impression that any psu can just start to fail. My overclocked system was running an Antec Truepower New Blue 750W psu. Recently it began misbehaving. Periodically the machine would just quit, all lights off, including the psu LED. Then it would restart (set in BIOS to restart after power off). I watched this. During a normal restart the psu LED never turned off, Molex-powered fans never stopped. But with this uncommanded poweroff, everything stopped, and the frequency was increasing.

The behavior reminded me of what people report from gaming when they overdraw one of their 12v rails. Yet this psu is advertised as being able to supply 25A per rail (300W), and I doubt my oc'd cpu (drawing 176W according to the Antec pus calculator) + mb drew more than that. So I reverted to stock clocks and the shutdowns stopped.

I have replaced that psu with a Seasonic X-650. Fewer watts, but single rail. I'm back to 4GHz and no shutdowns. From this I tentatively conclude that the problem was in the psu, not the mb or cpu.

If a high end psu can fail, what can we expect of low-end psu's?

 

[theAnimal]

Yet this psu is advertised as being able to supply 25A per rail (300W), and I doubt my oc'd cpu (drawing 176W according to the Antec pus calculator) + mb drew more than that.

Especially considering that the 24pin & 8pin connectors are on different rails.

 

[ehume]

Especially considering that the 24pin & 8pin connectors are on different rails.

Thanks for picking that up. I misread my user manual.

 

[jonnyGURU]

If a high end psu can fail, what can we expect of low-end psu's?

ANY product can fail for ANY reason. Even a PSU factory with the best QC and no shortcuts has a failure rate of 0.5%, so a low end PSU is going to be that much more.

 

[mikeford]

ANY product can fail for ANY reason. Even a PSU factory with the best QC and no shortcuts has a failure rate of 0.5%, so a low end PSU is going to be that much more.

Outside of issues with known bad parts, a batch of weak caps etc., failures are often a roll of the dice with respect to a single example. A thousand power supplies will likely have a failure vs time bell curve, some amount of DOA, some that last for years, and a fat group someplace in the middle where 80% fail.

I haven't had any early failure issues on any of the 10 or so systems I've built in the last ten years or so. I buy and often reuse cheap cases with included cheap power supplies and 80% of the motherboards I use are cheap combo's from Fry's, ECS etc. Most of these systems get replaced or upgraded every 3 to 5 years.

OTOH a some of the cheap cases are used, ie pretested, so I skip all the DOA and early failures.

**************************** End of ramble, I'm semi convinced and will likely buy some nice power supplies.