Try a 6 hour round trip through summer traffic in the Lake District for this.
User - My Monitor is dead
Me : Have you checked the power?
User : Yes! The sparky has tested the socket and has verified the fuse in fine also.
Me : OK I will pop down with a new monitor
3 hours drive later I carry a 17" CRT up 4 flights of stairs
I am about to install new monitor and notice power socket is switched off - I flick the switch and monitor comes to life. I found out shortly after the user asked the sparky to check the socket and plug fuse which he did and verified both were OK, At no point did the user say to him this was because the monitor was not powering up and the sparky left everything the way he found it -plugged in and powered off!!!!!
I did learn after this call to ask a few more probing questions to users before arranging a site visit.