I love this kind of stuff. When you're sure the thing that seems to be happening couldn't possibly be happening, and then you find out that literally the speed of light is coming into play.
We had a similar problem at one of my first jobs where I was a programmer and backup network support guy. One employee was having a problem with his CRT monitor flickering. It was very subtle, but just enough to drive him nuts.
So we replaced the monitor with one that worked fine on another machine. Same problem. We tried replacing cables, power cords, and did a bunch of other troubleshooting things. Problem persisted. Eventually we replaced his entire computer. Same problem.
Finally I put his computer and monitor on a cart with an extension cord and wheeled it out into the hallway. The problem went away. It turned out to be bad electrical shielding in his office.
> The problem went away. It turned out to be bad electrical shielding in his office.
My Commodore 64 started "typing" of its own accord. We sent it to be repaired twice only for it to work perfectly when they tested it. Turned out after we got a bigger TV, we kept it too close to it, and the static electricity eventually caused the effect.
By the time the repair people got to it, it'd presumably discharged enough for it to stop, and it worked fine for a while.
Heh, reminds me of a cursed user I was trying to help in the mid 90s.
Sold a person a computer, they said it bluescreened when they used it. So we picked it up and tested it. No problems. Sent it back, bluescreening again. So they came to the office with the computer. I set it up and used it for 30 minutes with them there, not a single issue. The moment they touched the mouse the computer bluescreened. Replaced the mouse and the problem went away.
I once worked in a lab where all computers had its own electrical stabilizer, but they were so poor that probably they did more harm than good. When someone turned on a stabilizer, the nearest CRT monitors would distort for a second, then flicker and colors would be degraded.
Luckily, my place was by the wall, so the effect was diminished, but it gave me big headaches. I lasted only 6 months in that company this being the biggest reason.
The stabilizer was triggering the degausser on the CRT. Turning on speakers or putting cellphones where a call was coming in would sometimes do this too.
We had a similar problem at one of my first jobs where I was a programmer and backup network support guy. One employee was having a problem with his CRT monitor flickering. It was very subtle, but just enough to drive him nuts.
So we replaced the monitor with one that worked fine on another machine. Same problem. We tried replacing cables, power cords, and did a bunch of other troubleshooting things. Problem persisted. Eventually we replaced his entire computer. Same problem.
Finally I put his computer and monitor on a cart with an extension cord and wheeled it out into the hallway. The problem went away. It turned out to be bad electrical shielding in his office.