Power on issues

I have dell optiplex 960 which has all of a sudden stopped powering on. I have tried switching power cables power socket but nothing seems to be working need help.
Kashif KhanAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

JohnBusiness Consultant (Owner)Commented:
Make sure all is very quiet, and the machine is OFF.   Press the power button and listen. Anything happen?  If not, the power button circuitry could have failed or the power supply could have died.  

Do you have a good voltmeter?  Open the case and see if there is any output voltage. CAREFULLY see if you can check for input voltage (120 VAC).
Andrew LeniartSenior EditorCommented:
Give it a swift kick in the case and see if that helps!  ( Joking! )  :-)

John's on the money. It's either going to be the button circuitry or power supply or in rare cases, a cable inside the case may have fallen off or gotten loose. I've seen this happen when a mainboard has blown too, but that's an even rarer occurrence.

By the way, 120 VAC is for the US. Here in Australia, it's 240 Volts. Other places in the world could be different again. But I guess if you know what a voltmeter is then you should already know what will be applicable to your part of the world too :)
If NOTHING happens (no lights, no fans, etc.) when you hit the power switch, then it is clearly the power outlet, power cord, power button, the motherboard, or the power supply that is the issue.  By far the most likely is the power supply.

To measure the AC voltage (120/240) inside the case on any computer in the last 15-20 years requires opening the case on the power supply.

There are very inexpensive ($7.50 in this case) testers that you can use to test the power supply and before it: https://www.amazon.com/Insten-24-pin-Power-Supply-Tester/dp/B005CTCD6S/ref=sr_1_6?ie=UTF8&qid=1519362030&sr=8-6&keywords=computer+power+supply+tester&dpID=51oGO0bfPqL&preST=_SY300_QL70_&dpSrc=srch
This will eliminate the motherboard and power switch (assuming you disconnect the power supply from all devices).  If that fails, it's either the outlet into which you have the computer connected, the power cord, or a 110/220 switch on the outside of the power supply.  Again, the power supply is the most likely culprit.
RaminTechnical AdvisorCommented:
Try to clear CMOS data and check if that helps.

Power off the PC.
Open the case.
Remove the Battery.
Locate the 3-pin CMOS jumper (CLR CMOS) on the motherboard.
Remove the jumper plug from pins 1 and 2
Place the jumper plug on pins 2 and 3 and wait approximately 5 seconds.
Replace the jumper plug on pins 1 and 2
Ty to boot normally.

More info:

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.