Optiplex 9020 Behavior when power up

Just a question for bettter understanding - What is your main language?

What I got from your question is that when you press the power buttton on the computer the lights blink once or twice then turns on?

This sounds like computer is coming out of sleep or hibernation mode.

Pressing power button on keyboard has same effect if in sleep or hibernation.

Wake on lan happens without any physical interaction by detecting lan pulse from any source - router will turn computer on constantly when not in use by doing normal connection tests.

Wake from sleep of hibernation will not give you access to the bios because the computer has passed  the boot stage - must do a restart or power off to access the bios properly.

Let me explain you detail and step wise.

Connection :

1. UPS is connected to main power supply plug in house.

2. I connected Optiplex MT CPU , Monitor , Router with UPS

3. I shutdown the computer.

4. Switch off UPS

Now after few minutes 

1. Switch on UPS

At this time I can see light blink of lights in CPU.

Hope now it is clear to you.

Thanks,

Even when a desktop is powered off, it consumes a very small amount of power to enable features like Wake on LAN, etc. So, when you turn on the power at the wall, these circuits get energized. I presume that is what is happening in this instance.

Thanks for reply.

I monitored behavior different way.

In my BIOS Setting Wake on LAN is disable but there are many other power management option (Like Deep sleep , USB Wake etc).

BTW till yesterday i removed network cable and work on computer ( start and shutdown few times) Now it is not blinking.

So it is sure it has something to do with LAN cable as today morning I connected cable and see the behavior again.

Now I look for user manual or if you have any suggestion let me know.

Note:

Unplugging may initiate Hibernation/Sleep saving mode. Not sure, Had it happen once.

Best to do a full shutdown via the desktop "Shut down".

Hibernation/Sleep will do seems to be a Startup but is really a Wakeup & Restore to last while in use.

Flashing Light ( not POWER light ) is system hard drive check on Startup/Wake.

Sorry took so long to get back on this.

This is a last resort option that should work.

1. Go to network adapters page ( Network Properties). Network and sharing Center.

2. Go to "Change Adapter Settings". (top left on screen).

3. Left click on local area network = network connection.

4. Choose "Properties" at bottom of list.

5. At top is the Network Card in use. Click on "Configure"

6. Go to "Power Management" tab and uncheck everything.

7. Optional: Go to "Advanced" tab and disable anything that says "Wake on".

select OK/Apply - exit back to Desktop - Reboot - Check settings given above above.

This the OS/Driver controlled settings of Network Card. Hope I didn't  repeat my self.

Everybody: REMEMBER = RELOAD the OS = MUST REDO ALL SETTINGS