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Changed power supply but pc still does not power up

by donjet26 / February 5, 2010 1:16 AM PST

I have a Gateway GT5028 with an AMD dual-core process running Windows XP that would not power up. I changed out the power supply but it still does not come on. There is a blinking light on the back of the new power supply but that is the only sign of life I see. Any ideas of what else it could be... and is there any way to test or check to see if the original power supply was actually ok or not?

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Lots of 'PC Power Supply Testers' available ...
by VAPCMD / February 5, 2010 2:20 AM PST

your favorite search engine will produce many.


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Changed power supply but computerr still won't start.
by sheldontraceySWT123 / February 5, 2010 9:57 AM PST

Since the power has to go through the mother board (main Board) that is where the problem may be. As much as I hate to say it, that is more likely the case.

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No power
by Marysvilleman / October 11, 2015 6:30 PM PDT

I'm having the same problem, the PSU seems fine but still no power, don't know what else to check.
Also there's no light on the MOBO.

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This is a 2010 discussion.
by R. Proffitt Forum moderator / October 12, 2015 8:28 AM PDT
In reply to: No power

If it doesn't have your answer a new post is best with full details.

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Yes. it sounds like the motherboard...
by Fredxxxxx / February 5, 2010 10:51 AM PST

but before coming to that conclusion, is the computer acting in exactly the same way now as it was with the old power supply? If not, you may just have a different power supply problem (wrong type or specs, not properly connected...)
Also, try a different power point (at the wall) - the one you're using may be having problems.
I suppose the new PSU came with a new power cord and you are using that.
Sorry to ask the obvious, but you have remembered to turn on the switch on the PSU, haven't you (if it has one).

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How did you check the power on switch?
by R. Proffitt Forum moderator / February 5, 2010 10:54 AM PST

Just checking.

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Good thought - the power on switch.
by Fredxxxxx / February 5, 2010 11:12 AM PST

Check the switch connections. If they're OK, and you know what you're doing, you could try shorting across the switch connections to see if that gets things moving.
Does anyone know if a dead or poorly connected CMOS battery would have this effect?

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Yes a dead CMOS battery
by R. Proffitt Forum moderator / February 5, 2010 11:29 AM PST

Or the CMOS clear jumper in the wrong place can stop power up. Simple to check so "do that!"

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Just tested Power Supply
by donjet26 / February 5, 2010 11:54 AM PST

I took VAPCMD's advice and got a power supply tester(CoolMax PS-228). I tested both the old and new power supply and both seemed to be ok. Although the old one did show 4.9 on the +5v, 11.8 on the +12v1, 3.2 on the +3.3v and 210ms on the PG display(what ever that is) but they appear to be in the ok range. The new one was pretty much right on except for +3.3v which showed 3.2 as well, 12.2 for the -12v and 270ms for PG.

When I installed the new power supply the green light on the back of it blinks on and off with all of the ps connections connected and also with just the main motherboard connected. The old one does not have this light. If I unplug all the connections from the pc and leave just the power supply connected, the light stays on solid. I think it is trying to tell me something. Unfortunately the new ps did not come with any information on the meaning of this light.

Now guess that pretty much points to the motherboard as the culprit. Is this the point which I just have to take it in to a professional (best buy/micro center, etc) to have it analyzed or are there any other things a willing hardware repair novice could try?

I will try the other suggestions in the posting that everyone has so graciously provided.

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Why is the cmos battery suspect?
by R. Proffitt Forum moderator / February 5, 2010 11:58 AM PST

And did you use a jumper or other switch to power up? I'm always ashamed when I forget to check that switch.

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More things to try...
by Fredxxxxx / February 5, 2010 2:31 PM PST

Can you see an LED on the motherboard when you turn on the power? There should be one and it should be on when power is connected.

Take out all your RAM and see if anything different happens when you try to boot (you would normally get a series of beeps).

Do the fans run? I'm guessing not.

Check all your connections inside the computer - and perhaps check again that you have connected all the connectors on the PSU (including the 4 pin connector).

Do you have the correct voltage setting on the back of the PSU (if there is one).

Try this:
Remove the power cord, hold the ON button in for about 20secs (to disperse internal power), then put the power cord securely back in, and try to boot.

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by goldilocks20 / February 5, 2010 6:57 PM PST

If PC shuts down while in BIOS, it could be due to overheating, fan rpm too low or stopping, unstable voltages or RAM problem. If PC does not shut down for an hour or more while in BIOS but only shuts down while in Windows, it is likely a software problem.

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I have to agree with geoffwaddell...
by Brechan / February 5, 2010 9:31 PM PST

I have to agree with geoffwaddell on his checklist; other things to consider trying:
Connect just the motherboard, see if the power light stays lit constantly.
Then connect one component at a time (hard-drive, graphics card, optical drive, etc.) checking to see if the power light is still lit constantly.
If at any time the power light flickers (during this process of elimination) then this certain component might be the culprit from keeping your computer from powering up.

The one thing you did not state in your original post was what the wattage was on your old PSU compared to the new one; if the wattage is too low (on either PSU), your computer will not power up, let alone boot.

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Changed power supply and will not power up.
by stynor / February 6, 2010 4:28 AM PST

On my wife's Gateway laptop computer, one of the memory modules went bad. Try removing the modules and starting the unit with only 1 module in the A slot. If it starts, try the other. If it does not start, bad module. If it starts with both modules, you have a bad slot B. Also try to use slot B if neither module will boot in slot A. Picked this tidbit up from an old Geek who began his career working with DOS back in the stone age.

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Power Supply problem fixed now
by donjet26 / February 8, 2010 1:29 AM PST

I have identified my power supply problem.... and it was not the power supply after all. It was a bad media card reader that was plugged into the mobo. After checking each power supply connection individually, the only one that caused the power supply light to blink was the main mobo connecter. Next I checked each connector to the mobo by individually unplugging each one. This was pretty easy to test. Once I unplugged the media card connector the ps light stayed on. To verify that it was the component and not the connector on the mobo I plugged the media card cable into another connector that was working and it also failed. Now I just need to replace the 9-1 media card reader.

Thanks for all of your great suggestions. I shall return the next time I need help with a problem.

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