A PC & VDU seem to have related problems:

The VDU click-sounds & power-light-flashes at approx. 1 Hz before
it's usable. More so in colder weather. Now [in s. hemisphere winter]
it never reaches the threshold.

Q - is this apparent 'warm up threshold' adjustable inside the VDU ?

I've replace the VDU - for possible later summer use;
BUT the previously existing 'difficult to start PSU', now is a 'refusal to
start PSU' -- also when I disconnect the replacement VDU.

Q - what tests/measurements can I make to debug this problem ?

== TIA