Last time I opened it up, to replace a noisy fan, I managed to wreck
the ribbon connector for the card reader + one USB slot - all were just
push connectors, apart from this which had a flip up type bar to
tighten. So I have been keeping my eyes open for a replacement m/board,
since then.

I spotted one on ebay, made an offer, 'won' it and delivered this
morning. Board installed, powered up and all looked OK in the initial
boot, until it got to Win10 - then the horizontal of the display went
like an old CRT where the horizontal was slipping, diagonal line
across.

Rebooted and second time around, it went to an Outlook screen, wanting
me to log in with my Outlook email address and password, which I
couldn't remember the password, but I could get access only once I
could get into Windows. The 'forgotten password' system was down.

Tried a third reboot, then a fourth one with the same result. At
attempt five, it all booted up just as normal into Win10 and all
working fine.

I sort of expected I would have to ring Microsoft, to reactivate
Windows, due to a component swap.