Anyway, none of the above explains why the picture went dark all by itself. So I had an older Acorn AKF...53? A 15" monitor. I quick brought that it, hooked it up. It worked fine. So I could breathe a sigh of relief that the computer wasn't freaking out. If something happened to that graphics card, I don't know what I'd do. I don't exactly have a ready source of VGA graphics cards, certainly not ones sexy enough to make XP happy! Somewhere I do have a CGA adapter with about 32K on-board, d'you think I could run XP on that? ☺
I noticed the monitor was quite hot on top. Nothing new there, but I'd feel happier if it was cooler, if only because it is kinda warm in my room (around 23°C; and 27°C outside); and hey presto! not more than two minutes later the monitor made a soft click and all the colours came back!
This got me to thinking. We all put a lot of care and attention in to keeping our computer cool. My motherboard (PSU?) is 36°C, my harddisc is 37°C, the processor is 34°C. Oh, and while we're at it, the cooling fan (I'm not entirely sure which) is running at 5579rpm. We know these devices generate heat, and we've taken measures to keep the parts cool.
But what about the monitor?
It is a high-precision device that... generates heat. Now name me a domestic monitor with a built-in fan. I've certainly never seen one. Until today... ☺
This is where I feel I must congratulate the Super U chain of supermarkets. They have introduced smiling wheelie-bins to their packaging to serve as a guide for correct disposal, with the slogan "Faites le bon tri!" which means, essentially, "sort it well!".
The first version is for a simple "chuck it in the bin". It is from a pack of traditional light bulbs (you know, the ones they want to get rid of soon). In honesty, the cardboard packet could be recycled, but the problems of getting a light bulb in the recycling means it is easier all around to say "chyaaackeeeiiittt".
It turns out, and easy to see if you flit your eyes around, or use a fairly slow digital camera, that the white light is actually composed of three colours, a red and a green and a blue. This might sound expensive, but in reality it means you could get away with a much smaller imaging system. Make the imager responsive to all light and then simply switch which one is being used (red, green, or blue) by altering the light. As it is the same sensor, there is never a problem of optical misalignment.
It is only us slow humans that see a white light, as our eyes and brain don't usually respond quickly enough so it all blends together. The same general principle works for television.
Anyway, the picture below. I set the scanner to do a 'pass' with the lid open, and while taking the picture I tilted the camera down, then back up again. The colour changes are quite obvious.
