Acer 5920G white screen conundrum

I am upgrading and repairing this laptop for my nephew, its a core 2 duo it was upgraded from Vista to Win 7 to Win 8 and it had lots of issues on Win 8 including that it white screened after 20 mins from cold and so I decided it would be wise to upgrade to a more stable and supported Windows version (Win 10) which is above the min requirements for windows 10 home 64b and therefore no problem so I upgraded it to Windows 10 after first completing the following:

1. Installed a new bios battery.

2. Upgraded the bios firmware. This is not a UEFI system so in theory could have had a legacy bios virus.

3. Cleaned the cooling system.

After upgrading it runs surprisingly fast on Windows 10, but the white screen problem was still prevalent and here's the conundrum. Using the process of elimination I performed the following tests:

A. PSU Issues - I checked output of the power supply was present an the correct voltage/amperage (19v/4.7A) for the laptop and it is.

B. Faulty or malfunctioning Graphics card - i Connected it to an external monitor which worked fine - Not a Graphics card issue.

C. Graphics/Monitor driver Issues - both were up to date and working correctly, however since drivers for the LCD monitor are no longer updated by the original manufacturer, Microsoft drivers are the only option. I though this might be the issue, Windows says the Monitor driver is working but I wasnt so sure?

D. An LCD hardware failure or loose connector - I thought was most likely - All connectors are fine, I purchased a replacement screen, but that white screened too.

E. Tried another OS. I removed the HDD and ran Ubuntu 18.04 LTS from a flash drive and it still white screened. So its not a microsoft lcd driver issue.

I seem to have tested and elimated all possible causes, any ideas?

Accepted answers

JackE

The video ribbon cable likely has a conductor trace break in the congested hinge area from opening/closing the lid too much. Less than $20 with free shipping. https://www.amazon.com/ShineBear-Screen-Video-Aspire-DD0ZD1LC000/dp/B07NPJ29GK

Jack E/NJ

JackE

The LCD inverter board is the next suspect. Jack E/NJ

All comments

JackE

The video ribbon cable likely has a conductor trace break in the congested hinge area from opening/closing the lid too much. Less than $20 with free shipping. https://www.amazon.com/ShineBear-Screen-Video-Aspire-DD0ZD1LC000/dp/B07NPJ29GK

Jack E/NJ

SteveLfc

Thanks but as I said I have tested all the cables and connectors and have elimated any cable or connector issues completely. Also from experience as a hardware engineer I can tell you for sure that if it was a cable fault or loose connector the screen would flicker with horizontal lines and the background would be black and the problem would be intermittent and it would be noticable and obvious when you open and close the lid. Also note that I said I replaced the screen which includes a new ribbon cable.

JackE

The LCD inverter board is the next suspect. Jack E/NJ

SteveLfc

Thats it, cheers ACE ; that's got to be the exact problem since its clear that the screen fades to white after 20 mins and the problem is the same with both the old and new screens and obviously when this inverter fails you are left with a backlight, hence the white screen, I looked at the inverter when I disassembled the laptop, however it seemed to be working and I wrongly discounted since I've never seen an inverter failure in 25 years, it but its not obvious when you consult the LCD Inverter information on the acer website (see below) because all the symptoms and scenarios they've listed state that the screen is more likely to go black, however there is a scenario missing, in that, if the LCD inverter fails and not the backlight, end result = backlight only = white screen!

LCD inverter Information from the acer website:

TYPICAL INVERTER FAILURE SYMPTOMS

Usually Aspire 5920G Series inverters fail in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.

2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.

3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the Aspire 5920G Series inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

SteveLfc

Sorry i accidentally set my comment as the accepted answer, when I intended to set JackE's answer pointing at the LCD inverter, and I dont have the credentials to correct it so i'll leave it to someone who has the privileges to do this mark only JackE's as the accepted answer.