PC No Post No OS No Beeps No Display No Bios

[FangTheHusky]

I've spent the past day trying to fix this failure. Running windows 10, I ran an installation of windows 7 (for dualboot) onto a clean partition on my HDD. Everything was going fine until the computer reset to continue the installation. After a few minutes I noticed that the PC never turned back on. So I pushed the power button and the fans and drives spin up, led lights also turn on. When the machine is powered on there is no post, no error code beeps, and nothing displays to the screen. I don't get the motherboard splash logo, I can't enter BIOS, and the screen remains with no signal.
Fixes I've tried:
CMOS Reset using motherboard pins.
Removed motherboard battery long enough to reset the system.
Unplug HDD and tried to boot from Linux Live Disk.
Removed RAM and received "No RAM" Error Beeps
Nothing I've tried works yet far. Any help would hopefully save my brick!

HP Pavilion Slimline 400-034 Desktop PC Product Specifications:

Joshua-H61-uATX (Joshua)
Pentium G2020
Memory Amount: 4 GB Speed: PC3-12800 MB/sec (runs at PC3-10600 in this system) Type: DDR3-1600
PSU: Internal 220W (100V-240V)

PC Specs Sheet @:
http://support.hp.com/us-en/document/c03791266

 

[fahim5001]

try the ram in different ram slot also try with another ram. if that dosent works try turning on without mobo battery.

 

[FangTheHusky]

try the ram in different ram slot also try with another ram. if that dosent works try turning on without mobo battery.

Just tried this, still nothing.

 

[fahim5001]

then could be GPU problem, since everything is running but no screen. check your display output port. or try removing the board to a test branch and add a gpu then see what happends.
or turn power on and after a while of running without any screen press f1, this will bypass any post message and try to boot your PC (if its a display output faliour issue)

 

[FangTheHusky]

then could be GPU problem, since everything is running but no screen. check your display output port. or try removing the board to a test branch and add a gpu then see what happends.
or turn power on and after a while of running without any screen press f1, this will bypass any post message and try to boot your PC (if its a display output faliour issue)

I don't have a GPU in the machine. Although, when I power on the computer, wait a few minutes, and press F1 the led on the my flashdrive flickers (it doesn't any other time). There is still nothing posted to the monitor although, if I then press the return key led that indicates HDD access flickers. So I'm almost positive there is some sort of menu open that I cannot see.

 

[FangTheHusky]

I cannot consistently reproduce this outcome though

 

[FangTheHusky]

Quick update! I got the machine to boot into windows. There IS some sort of menu showing up behind the blank monitor. Still no mobo splash and every time the system boots up it requires to what I assume is to "Select the Windows installation?".
When the machine booted the OS the first time a error message told "Your windows install failed, check online for comparability." (Paraphrase)