M251nw printer randomly freezes with white screen

[PPhawkeye]

Hello,
My Laserjet 200 color M251nw printer has been in operation for years but now randomly freezes with a white screen since a couple of years.

The printer is off most of the time and we power it on when needing to print.
What generally happens when we need to print is that she boots up normally and we can see a normal display but very soon (often less than a minute) the display turns white and the only thing we can do is shut it off and try again, which may take 10-20 times while getting on the nerves of everybody.
Sometimes - but by no means always - we can get by by putting the file to print on a USB key and inserting the USB on the printer.

I had already updated firmware and reinstalled the printer on Windows 10 a while back and it seemed that the problem had gone away but unfortunately not...

Yesterday I browsed through the troubleshooting manual and decided to test the display.
As I didn't need to print, the printer stayed normal during 30-45 minutes without any problem whilst I did my tests.
No abnormality with the display or whatsoever was found.
Today same thing (i.e. no white screen) as I was checking the error log, the only error I'm not sure of is 41.3000 Unexpected size. Updated firmware to latest 20150212. 
Tested using HP Print and Scan Doctor 5.6.2 no issues detected. Guess I'll face the problem again when someone will urgently need to print... 😞
 
I wondered whether there could be a physical connectivity problem between the display and the printer but haven't yet found instructions on how to check and potentially correct that?

Other than that, I have exhausted my list of ideas but perhaps somebody here has some others.

Many thanks in advance.

[PPhawkeye]

Of course when my daughter needed to print just now, she got the white screen...
...and I got screams 😞