Just to recap - Over past few weeks my W10 Acer laptop had more and
more frequently locked up, no mouse movement, no response to ctrl+ Alt
+ del, only holding the power button down for ten seconds to reboot it
brought it back. Manually taking control of virtual memory and upping
the amount, seemed to fix it, it did, but not for long - so nothing
else for it but to open it up....

Nothing was socketed, apart from cables to accessories like the
keyboard, mouse pad, a USB + memory slot and wifi module. No socketed
chips at all, 8Gb of ram, none socketed and no expansion slots.

I managed to break the socket clamp catch for the tape type ribbon
cable for the USB + memory socket, trying to work out how to release it
- It was a matter of easing the keyboard a little way, to begin
reaching in to unplug things, some had a catch clamp which pushed in,
others like this had a clamp which needed lifting 90 deg to release.

I dusted the entire PCB, case and air ducts out thoughroughly with a
paint brush, then reassembled it, with no expectation that the lockup
was fixed. The damaged socket I partially botched by using a bit of
sweetie wrapper to wedge it and apply contact pressure.

No more lockups in the several days since then, despite changing it
back to W10 default virtual memory management - that USB + memory
socket has power, but no data, so obviously the cable has pulled
partially out/ not making full contact, in my rush to get it back
together.

My best guess as to the problem - maybe a bit of loose solder or
conductive dust shorter something out. The brushing cleared it out.