OS 10.4.6 and display connector

Question

In March I got a G4 Mini to replace my old Mac. In the formidable process of getting all my functions to work on the Mini, I would have to swap computers several times, so I did not screw the connector from my monitor to the adapter on the Mini.
In a month, I removed my old Mac from my desk. In the next two hours, my Mini's response to mouse clicks was a little erratic. Then the screen went blue. I reached back to be sure the display connector was seated.
I restarted and the screen remained blue for several minutes. I restarted again and saw faint flickers of my desktop. In a few minutes the desktop suddenly appeared. I could find no indication of trouble in the logs.
It worked fine for eight days. Then the response to the mouse and keyboard became slightly erratic. The next day I started the computer and told Internet Connect to dial. The screen went blue, but there were a couple of flashes when I saw that Internet Connect was keeping track of my online time.
Six times I restarted and let it sit five minutes with a blue screen. Once I disconnected the power supply for five minutes. I zapped the PRAM. It looked fine on the Install disk, which found no hardware problem, but blue was all I got from the hard drive.
I removed the Mini to use my old Mac to find Apple's phone number. When I hooked up the Mini two hours later, I screwed down the display connector. I had to back out one screw a turn or two so the connector would seat fully and I could engage the screw. The Mini started immediately. The System Log seemed to say that all the startups that day had been normal. I could find no record of a crash in the last few days.
Was the problem ambiguous continuity in the connector? I want to be sure. Is OS 10.4.6 more sensitive to a display connector problem than is the Install disk? Under 10.4.6, can a problem in the display connection cause a misreading of keystrokes and mouse clicks?

Answer 1

Welcome to Apple Discussions!
If you "reached back" as you say, you may have
inadvertantly bent the connector plugging it into the
Mini. The bend may be ever so slight as to not be
noticeable, but the computer would be sensitive to
it. When dealing with computer connectors, it is
important to remember to pull them evenly out and
push them evenly in, being observant that the pins
are matching the holes, and not move them at an angle
from each other when the connection is taking place.
What I called "reaching back" was reaching forward. It was after the screen turned blue. I could see the connector on the back of the Mini. I pushed it directly toward the connector on the Mini. Nothing moved, so I assumed it was fully seated. I didn't realize the screw might have been interfering.
Try a different display to see if the connector of
the display itself, or the connector on the Mini is
what is damaged.
I assume screwing the connector down during the second incident has eliminated the possible electrical problem.
Activating the dialup connection may have triggered
the display to go wild if something is wrong with the
connector or cable's shielding. It is unlikely to
happen because the voltages and RF created by the
modem is so little, but I wouldn't say it is
impossible.
Making the dialup connection proved that the computer continued to work after my screen went blue.
The fact the logs say nothing suggests the problem is
more than likely to be just between the connectors
and cable.
That sounds right to me, but I want to understand two loose ends in case something else is wrong:
1. In each incident, why was the first symptom an inconsistent response to mouse clicks?
2. Why did it work fine when I booted from the Install disk?
Your reference to RF may point to the answers. I should look at a pinout to see where the sync pins are in that connector. Suppose the screw was keeping the connection physically open on one side so that a sync pin was barely making contact. If it opened to the point of invisibly tiny sparking, that could have interfered with the click signals of my wireless mouse.
If the connection opened a couple of microns more, I would have lost my sync. I wonder if the loss of a sync signal causes an SVGA CRT monitor to go blue.
Why would I still get a display if I booted from the Install disk? It probably had a different refresh rate and maybe a different scan frequency. In the case the sync voltage may have been high enough to jump the bad connection.
If that's a reasonable explanation, I can feel confident that the only problem was an unscrewed connector.