Compaq elite 8300 cannot boot

[SMD3]

Hello, I have a HP Compaq Elite 8300 that has been working fine for several months then one day would not boot. When the power button is pressed two green lights flash and the fan rotates for about 1 second then everything stops. I've been through the online trouble shooting on the HP website but no help, I've switched outlets, switched power cords, did a hard reset, unplugged DVD drive and all other peripherals, unplugged and reinserted the memory cards, checked all connections inside and out but still not booting.

Any assistance would be greatly appreciated.

Thank you in advance.

[WAWood]

@SMD3 

To determine the cause with hardware failures, you have to be able run diagnostics. We have no way of accessing your PC from here, so we can not do that for you. You have to do it yourself.

You do this by pressing the Esc key repeatedly when rebooting and then, when the HP Startup Menu appears, selecting Diagnostics (usually F2) and letting it run.

If it is NOT possible to run diagnostics, or if that does not work, then there is NOTHING more you can do by yourself -- and there is NOTHING we can do because we have no way of accessing your PC from here to run diagnostics or repair hardware.

You will need to have the PC physically examined in a service facility by folks that can run their own diagnostics to determine what is wrong with it.

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If your PC is still under the original one-year HP warranty, or if you have purchased an extended warranty from HP and this is still valid, then having HP do this is an inexpensive option for you. In that case, you should contact HP Customer Support to see about having it repaired or replaced under warranty.

To contact HP Support see the following link to create yourself a case number, then call and it may help speed up the call process:

Step 1. Here is the link: https://support.hp.com/us-en/contact-hp
Step 2. Enter Product number or select to auto detect
Step 3. Scroll down to "Still need help? Complete the form to select your contact options"
Step 4. Scroll down and click on: HP contact options - click on Get phone number

Case number and phone number appear.
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If your PC is no longer under warranty, then it will cost you up front to have HP examine your PC. If you want to do that, you will have to contact an HP Repair or Service Center to see if they can examine the PC to determine the cause(s) of the problems, if it can be repaired, and an estimate of the repair costs.

Since you live outside the U.S., here is a link to HP Service Centers, by Country/Region: https://support.hp.com/in-en/service-center

Good Luck