Upgraded from W10 1803 to 1903 now I get no video or control of PC

I have upgraded an HP pavilion p6 series Model: p6-2370ea i3 processor 8Gb Ram.
I've been running Windows 10 ver. 1803 for years.
Anyway I read that 1803 will soon become 'outdated' therefore decided to upgrade to 1903.
After I upgraded it seemed to go OK for a few days then it wouldn't boot, but then did after a few attempts.
anyway, then I restarted it and it and I couldn't get any video out of it.
I also note that it seems the keyboard isn't working (Caps lock & Num lock don't light up).
The fans turn and the hard disk spins up, so does the DVD.
I've been trying for a week now and I cannot get any video out of it.
I've replaced and 'proved' the monitor, keyboard, mouse & PSU
I have multiple of those units and using them now on a spare PC.
Also I can't get any 'beeps' from the PC
I've removed the memory & swapped the slots & tried one at a time
I'm not using a graphics card, only onboard video (normally use both slots, but tried one at a time)
Checked the 4-pin power (& different PSU)
Removed the CMOS battery to try & reset the bios
Tried booting from a linux boot disk but still no video or any sign of booting (Although I can hear everything spin up as though its booting).
There IS power at the USB ports front & rear (tested with seperate USB light module)
I've also tried different modes of booting F8, F12 etc
Any new sensible ideas welcome.
Thank you in advance

Find a flash drive (> or = 8 GB)

Create a HP diagnostics UEFI flash drive:
https://www8.hp.com/us/en/campaigns/.../pc-diags.html

Run the HP diagnostics to test all hardware > use a camera or smartphone camera to take pictures > post images into the thread

If there are problems posting images please use one drive, drop box, or google drive share links.

Hi zbook

Thank you for your resonse.
I downloaded sp98431.exe which is the test program from HP on your link.
I'd post the pictures you asked for, but it would be easier for me to simply draw black rectangles, sadly.
I still get no video or response from keyboard.

My guess on this situation is that I've either got a faulty motherboard (Damn convenient following a Microsoft update!) or my Windows update has corrupted my BIOS.
I can't seem to boot anything from hard disk, DVD/CD or USB drive.
I get nothing on any monitor (leads & monitors are proven to be good)

I had a similar issue with a similar HP model (difference was that mine was W8)
Installed another hard drive from another identical model and all was well.
Re-installed the original hard drive and all was well also??????

I had removed ALL attached USB devices and tested each one to see if they were to blame.
All passed except for the WD MyBook we use for backups (and it was attached to the front USB ports)
I still haven't fully tested the WD MyBook and it's cable - but there's nothing plugged in the front USB and the system has been working fine for a while.

I suspect that a Microsoft/Windows update exposed an existing problem with either the front USB ports, the USB cable, or the WD MyBook and that's what caused the black screen.

So, to make a long story short, unplug everything but the mouse, keyboard, and monitor (I had a great fight with the wife because I uninstalled her USB sound card!) - then try another hard drive. If you don't have a spare, try purchasing one from a shop that'll let you return it (for your money back) if you don't need it.

Tech44 said:

Hi zbook
Thank you for your resonse.
I downloaded sp98431.exe which is the test program from HP on your link.
I'd post the pictures you asked for, but it would be easier for me to simply draw black rectangles, sadly.
I still get no video or response from keyboard.

My guess on this situation is that I've either got a faulty motherboard (Damn convenient following a Microsoft update!) or my Windows update has corrupted my BIOS.
I can't seem to boot anything from hard disk, DVD/CD or USB drive.
I get nothing on any monitor (leads & monitors are proven to be good)

My computer had so many issues after upgrading it to the 1903. I thought it was a hardware issue like PSU, Ram ...etc and after testing all the hardware I did not find anything wrong with it. Did a fresh install of the previous Windows 1809 and all the issues went away. There is something going on with 1903 that some computers are not taking too well too it. Before you do any hardware testing or replace parts, try to do a system restore to 1803 or flash a fresh install of 1809.

Run through these POST beep codes and troubleshooting steps:

What is POST?
Computer POST and beep codes
POST troubleshooting steps