Power supply problem?

[Ai Haibara]

Well, our Vista system appears to have died, tonight. Not sure what happened - there weren't any noticeable signs of power supply problems that I saw, up to this point, but...

Another family member was using the system, just browsing the web when the system shut off, and wouldn't come back on. Nothing happens when I push the power button on the front... no lights, no activity, and the fans don't even spin. There's a little green LED that's lit on the back of the tower where the power supply is located, beside the plug jack and the voltage switch, but I don't know if that means there's a problem with the power supply, or if it just means it's still receiving power.

Is it possible to buy a new power supply and replace it myself, if it's indeed dead? I haven't replaced a power supply since... oh, 1998-99, or so, and I don't know if it's still as easy (or even if anyone would recommend it).

(Windows systems must really have it in for me, at the moment...)

[aedipuss]

holy cow batman, what are you down to a win3.1 working unit tonight? yes p.s.'s are still replaceable, not much has changed there. check the wattage on the one that died and get a slightly bigger one.

unplug it and wait a minute, then hook it up and try it again. if it doesn't even give a beep when you press the power button, the p.s. is probably dead.

newegg.com is a pretty good supplier.

[Ai Haibara]

No, but I could always drag out the old Win3 laptop, if I wanted. (Not that I could connect to anything with it...)

Yeah, I disconnected the power cables, waited about five minutes, then reconnected them (originally), and nothing happened. I'm leaving everything off for a while (perhaps overnight) to see if anything changes, but I'm not going to get my hopes up.

Just surprising that the power supply would go out, since I haven't seen any signs of it failing (the last time I had to replace a power supply, the signs were fairly obvious).

[fatbloke88]

Before you run out and get a new power supply try shorting the power switch terminals on the motherboard wit a screwdriver to make sure it not just the power switch.

[TBoneit]

Sounds Like a HP, if so look at the depth of the power supply. Some of the HP computers do not have the room for a full size power supply. We've had to stock shorter than usual for that reason.

[INFRATOM]

When power fluctuation happens very easily could damage a computer, use a power surge protector. And your power supply may not be the only effected part, so motherboard and hard drive could be damaged too among other things. If you want to buy a power supply most often there is a case on sale coming with the same power supply cheaper, keep that in mind. Most retail computer systems that sold as a deal is based on obsolete systems, if it was a cheapo system in my opinion does not worth repairing in these days you can buy a newer one around $350 and add the RAM and HD to the new one. Option 2: in some sales if you wait or if you have a Fry's near by they put power supplies on sale for cheap price every now and then. If you changed power supply in 99 it is still the same but make sure it is only the power supply and the only way to find out is to swap it with a good one. Make sure wall outlet has power too.
Don't short anything as suggested above!!! you could damage other things besides the safety concern. If you bought your computer at least 2 years ago same computer or better could be made with $250. A good power supply is going to cost you around $70 at least that's almost 1/3 of the price of a new one. Economy rules most things are disposable.

[Po|arbeaR]

An easier way to check if it's the switch is that "most" motherboards have a small LED somwhere on it and typically it's green if the board is indeed getting power. Replug power cord back in and peek inside and see if you see a light on the board, If you don't I would say the power supply is dead. If you do see the light, it might possibly be the switch although highly unlikely. Other thoughts might be to see if as suggested above try another power outlet in the house and ALWAYS use a good surge protecter. Let us know of your progress.

-PB

[Ai Haibara]

Well, the power supply has a light beside the plug and voltage selector as seen here:
http://h10025.www1.hp.com/ewfrf/wc/document?dlc=en&lc=en&product=425925&lang=en&cc=us&...cname=bph06788

(No, that's not my system, but it came up on a web search.) It's on constantly (even for a while after I disconnect it from the power), which does indicate it's getting power. The above page also seems to believe that if the light's constant (not blinking), then the power supply's probably okay and there's a different problem.

I've tried different outlets. The only thing I haven't tried, yet, is unplugging all the components as listed on that page, and seeing if the light's behavior remains the same.

BTW, I went ahead and picked up a slightly more powerful power supply this afternoon (300 > 350)... but the main connector on the newer power supply didn't match - the original is longer, and has 24 pins as opposed to the new one's 20. Just curious - even if it doesn't turn out to be the power supply, what should I look for to make sure I'm getting the right main connector? I don't know if it's listed on the box...

TBoneit: It's a Compaq. (Yeah, I know... Compaq=HP, to some extent. ) The power supply appears to be full-size.

INFRATOM: I know, but I'm just vainly hoping that I don't have to replace anything else. :I I always keep everything on surge protectors.

fatbloke88: I don't know... I'm a little wary about doing something like that, and some of the pages I read in the same search I was doing above don't think using a screwdriver to short (capacitors, though) is a good idea.

[budz]

Just buy a ATX 20 pin Female to 24 pin Male Adapter for that 300- 350 watt power supply you bought. The cost is cheap at $2.99 at SVC.com

http://www.svc.com/glatx2024-11.html

[Ai Haibara]

Do they sell those adapters in regular stores? (Just curious, again.) I don't recall seeing anything like that in any of the stores I checked, today.

I've tried disconnecting the power adapter from everything (well, not the tower frame ), and then plugging it in - the little light still comes on and remains on without flashing (still, even for a while after I turn off the power/pull the power cable.) I've even tried that HP method of holding in the power button for five seconds to discharge the power, but that doesn't seem to change or help anything.

Probably a rather stupid question: Would the front-power switch going bad cause the first problem (where it unexpectedly and abruptly shut off while another family member was using it)?

[gll99]

If this is a standard atx case the ps is very easy to replace. It only takes a few minutes.

The fact that there is some power that lights up a led doesn't mean anything. Some I replaced wouldn't power the agp slot so the video wouldn't display making it look like the video card was flakey while it was making boot sounds and the led was showing hdd activity but it was the ps. No matter what it's good to have a spare ps on hand.

[budz]

Do they sell those adapters in regular stores? (Just curious, again.) I don't recall seeing anything like that in any of the stores I checked, today.

Go to a local computer repair shop and they might sell them or order one online. If you're in the USA mainland it shouldn't take too long to ship to you.

[redwudz]

If you can't find a adapter, the 20 pin will still work with a 24 pin socket. As long as you orient pin 1 correctly. The extra four pins aren't generally needed unless you have a PCI video card that draws extra power through the motherboard. They are hooked to the same wires as the 20pin. They just supply the same current/voltage that's spread among more connectors. Early PCI cards stressed the 20 pin connectors and caused overheating at times, so they added more connectors.

This page has a good explanation of how the PS connectors work: http://www.playtool.com/pages/psuconnectors/connectors.html Look down the page a bit to see what a 20 pin looks like plugged into a 24pin ATX connector:



If you think the front power switch might be defective, just pull the plug off the reset switch terminals on the motherboard and substitute them and use the reset switch to turn on the PC. Or jumper across the 'on' terminals where your front power switch is plugged in. These are logic level terminals, so very little power there. They tell the MB to turn on the PS.

If that fails and the new PS fails to turn on the computer, you may have a bad motherboard. But hope for the best. Changing out the PS is a good first step, along with checking that your front panel switch is working. If the front panel switch failed, (shorted) it would just cause a orderly shutdown the same as pushing it when the PC was running. The PC wouldn't go off instantly. If the front panel switch didn't work (open). it just wouldn't start the PS, but it wouldn't shut it off if it was running.

Good luck.

[Ai Haibara]

With my luck, the video setup probably does draw extra power from the motherboard. It's one of the newer OEM Compaqs with the Intel video system (bleah).

I don't have enough confidence to mess around with the wiring/leads like that, though. Bad enough I'm paranoid to take apart my laptop and see if indeed, all it really needs to start working again is to replace the heatsink compound on the GPU.

[TBoneit]

General rule:

A bad power switch would not make it shut off in mid use.
A motherboard with intel built-in video will not use that much power. That is why your power supplay was that size.
Holding the power button 5> seconds will turn off the power.
Holding the power button or a power button that sticks on will make the computer turn on and then turn off after 5 seconds.
A cheap computer no matter who makes it is a cheap computer. (You get what you pay for)
IMHO Dell, Compaq, HP are decent computers. I repair them for a living. Some other brands, well..............
Build your own for the parts you choose, not to save money.
A brand name business model will be better built than a home computer for teh same specs.
Usually a Brand name will be quieter than a home built.



A Good computer shop should have a tester that can at least test whether all the different voltages are there in your old power supply.
It might be time to have a shop check it out. Where I am we charge $49 that rolls into the labor charge if we do the repair.

Good Luck

[INFRATOM]

You have bought an older power supply ..that's ok. The motherboard you are explaining with intel video most likely is the G31 chipset the whole motherboard sells for under $60. This kind of motherboard can work with low wattage PSU, so if you have an old computer try the PSU. There are a lot of throw away computers with pentium 3 or early p4 that came with 250 ~ 300watt PSU maybe you can get one of those from local garage sale. That motherboard can work even on 250 watts. Power supply may show it receives juice from the wall but a 5v or 12v could be burnt out. Only swapping with a good one will show. If this the computer you have in your profile with Pentium D and 1 gig RAM remember does not worth spending money on, only worth repairing by garage sale parts.

[Ai Haibara]

General rule:

A bad power switch would not make it shut off in mid use.

So, it's more likely to be the power supply?

(Yes, I've been more inclined to have someone look at it; I'm just curious, that's all. )

A motherboard with intel built-in video will not use that much power. That is why your power supplay was that size.

Does that mean the smaller supplies in the HP/Compaq systems draw more power, then?

Holding the power button 5> seconds will turn off the power.

Right. I was just mentioning that the HP troubleshooting page I linked to above said that unplugging the tower, then removing the power cord and then holding the front power button for five seconds was supposed to discharge any charge the supply was still holding.

A cheap computer no matter who makes it is a cheap computer. (You get what you pay for)
IMHO Dell, Compaq, HP are decent computers. I repair them for a living. Some other brands, well..............
Build your own for the parts you choose, not to save money.
A brand name business model will be better built than a home computer for teh same specs.
Usually a Brand name will be quieter than a home built.

I didn't mean to imply that it was a bad system, or that the Intel video was bad - the 'bleah' was only because I've had to deal with a new game another family member wanted to install - supposed to work fine with Vista, just NOT if you have Intel Video.

My only issue with the system was that it had 1GB of RAM as opposed to two, for working with Vista. Other than that...

A Good computer shop should have a tester that can at least test whether all the different voltages are there in your old power supply.
It might be time to have a shop check it out. Where I am we charge $49 that rolls into the labor charge if we do the repair.

Good Luck

Maybe. I've certainly been considering it.

[Ai Haibara]

Update: We bought a different power supply, with a 24-pin connector (just to be safe). I replaced the old PSU with it yesterday, and everything seems to be working fine so far (knock on particleboard). The whole system's now even more quiet than it had been with the old PSU.

INFRATOM: Maybe I've got to start checking more garage sales. The only computer/hardware I've seen at any of the ones I've passed in the last few years was an old P3 tower that looked as if it had been used as a server, but didn't really have anything in it by that time.