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for a few weeks now I've had an issue where I have to unplug the power lead for 30 seconds then plug it back in and hit the power button before the pc will turn on /come out of hibernation. Now this has stopped working too.

the green LED on the back of the PSU is lit up. I press the power button, the fan whizzes around for a second, the power button LED flashes for a second, then everything stops.

I thought maybe the button wasn't making good contact with the switch. I pulled the face off and pulled the switch out and pressed it directly. it still does the exact same thing.

There's no beeping or anything, so it doesn't get to do any motherboard tests. Can someone suggest some troubleshooting steps? is this a know issue with these machines?

UPDATE: After pulling the battery out/in and reseting the CMOS with jumpers and removing the external video card ( and plugged in the onboard one). Now when power is plugged in the power light on the front panel flashes amber continuously. The PSU fan doesn't spin. According to other forums this means the PSU is dead.

EDIT: looks like I'm not the only person experiencing this issue

EDIT: Link to the service manual & beeps codes

Followed steps to verify if the PSU is dead using the PSU paperclip test and checking outputs will a multimeter. The PSU looks fine.

PSU paperclip test is as follows:

Try to verify (as well as you can) that the PSU works. If you have a multimeter, you can do a rough checkout of a PSU using the "paper clip trick". You plug the bare PSU into the wall. Insert a paper clip into the green wire pin and one of the black wire pins beside it. That's how the case power switch works. It applies a ground to the green wire. Turn on the PSU and the fan should spin up. If it doesn't, the PSU is dead. If you have a multimeter, you can check all the outputs. Yellow wires should be 12 volts, red 5 volts, orange 3.3 volts, blue wire -12 volts, purple wire is the 5 volt standby. The gray wire is really important. It sends a control signal called something like "PowerOK" from the PSU to the motherboard. It should go from 0 volts to about 5 volts within a half second of pressing the case power switch. If you do not have this signal, your computer will not boot. The tolerances should be +/- 5%. If not, the PSU is bad.

I decided to go buy another PSU anyway. Even though I passed the paperclip test and I checked the grey cable with a multimeter and it was within range, a new PSU fixed the problem. Booted straight up. Thanks all for helping!

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2 Answers 2

up vote 1 down vote accepted

That sounds like a power supply issue or a video card issue. Considering the 545 is the newer version of my old 530, I'd probably suggest doing about the same things I did.

The 545 comes with both an onboard and an optional discrete card. The onboard card will not work if the discrete card is plugged in, and if that's what's causing your system not to boot up, yanking the discrete card, removing the cover over the onboard VGA port, and using it would rule it out. This is the cheapest thing to check, and what i'd start with. The 545 dosen't come with any video card that's notorious for failing, but its worth a check.

If it isn't the video card, (and since checking the capacitors already has been suggested), try swapping the PSU to one that you know works. Swapping the PSU will also increase the flexibility you have, should you want a better graphics card or other options, since dell's PSUs are a little odd and only have sata connectors .

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Thanks, it does have a discrete video card. I pulled it out, still the same. I noticed an amber LED lit on the motherboard as soon as the power is plugged in. Trying to find a manual to figure out what it means. –  Nick Kavadias Apr 1 '13 at 9:41
    
If I recall correctly its the light that says the motherboard has power. –  Journeyman Geek Apr 1 '13 at 9:43
    
Thanks @Journeyman your answer was great, helped me solve my issue. –  Nick Kavadias Apr 2 '13 at 3:47

Most likely with the power button likely working, the candidates are motherboard, PSU or CPU.

  • Open the case, look at the motherboard capacitors. Are any swollen or leaking (this would be a bad motherboard
  • Short the green and black wires with a paperclip to test the button. If this works its a bad button
  • Pull the CMOS battery and disconnect power, wait 5-10 minutes then reconnect both to completely clear the settings and test

If you get through all that and there is no progress or information then you would need parts to swap out to test further.

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