No RGB Signal warning, turns off then reboots

[helenQ]

I purchased a new computer and was using it for two days when I started to experience problems.

The first day I used it I had an enjoyable trouble free day.

The following day I noticed it started to show a red warning "NO RGB SIGNAL" and then turn off only to then proceed in rebooting itself again. It would stay on for a while and enable me to process my work, then without cause it would turn off and on again and showing the same warning about the RGB

This kept recurring over the course of three hours at which point it started to drive me nuts.

I've read a few posts on this forum about systems turning on and off but nothing appears to be similar to this.

a) Can someone explain what the "RGB Signal" is and whether the monitor could be the problem.

b) The technican who uploaded the software from the old computer opened the chassis of the new computer to gain access to the HD and I was wondering whether he may heve loosened something and if I need to get him back to take a look at it again.
He found when he tried to load directly from old HD to new HD via cable the new computer was turning on and off then. He eventually closed up the new computer and went about transferring the data from the old HD to a disk he brought back and installed.

He seemed satisifed that all was in good working order when he was finished.

Can someone please help?

[TT4Titans]

a) Can someone explain what the "RGB Signal" is and whether the monitor could be the problem.

Short for red, green, blue monitor, a monitor that requires separate signals for each of the three colors. This differs from color televisions, for example, which use composite video signals, in which all the colors are mixed together. All color computer monitors are RGB monitors.

An RGB monitor consists of a vacuum tube with three electron guns -- one each for red, green, and blue -- at one end and the screen at the other end. The three electron guns fire electrons at the screen, which contains a phosphorous coating. When the phosphors are excited by the electron beams, they glow. Depending on which beam excites them, they glow either red, green, or blue. Ideally, the three beams should converge for each point on the screen so that each pixel is a combination of the three colors.

Make sure the Video card is seated good and the monitor is plugged in securely. Go to Control panel performance and maintenance then system - hardware - device manager see if there are any conflicts.

[helenQ]

a) Can someone explain what the "RGB Signal" is and whether the monitor could be the problem.

Short for red, green, blue monitor, a monitor that requires separate signals for each of the three colors. This differs from color televisions, for example, which use composite video signals, in which all the colors are mixed together. All color computer monitors are RGB monitors.

An RGB monitor consists of a vacuum tube with three electron guns -- one each for red, green, and blue -- at one end and the screen at the other end. The three electron guns fire electrons at the screen, which contains a phosphorous coating. When the phosphors are excited by the electron beams, they glow. Depending on which beam excites them, they glow either red, green, or blue. Ideally, the three beams should converge for each point on the screen so that each pixel is a combination of the three colors.

Make sure the Video card is seated good and the monitor is plugged in securely. Go to Control panel performance and maintenance then system - hardware - device manager see if there are any conflicts.

Thanks TT4Titans for the explanation about the "RGB Signal" it helps to know what the warning means when it comes up on screen again.

Also I appreciate the advice on resolving the problem with the PC rebooting by itself.

I'm not sure though what you mean "make sure the Video Card is seated good" does this mean I have to open the PC to look iinside or is there another way to check.

[TT4Titans]

If you have a video card where the monitor plugs in.just take the side cover off and push in on the card.might want to take it out then put it back in.

[MrKnowItAll]

All color computer monitors are RGB monitors.

That is only true for VGA and later monitors. Prior to that color monitors used a digital RGBI interface and it was up to the monitor to do the color processing, all the graphic cards did back then was to copy the digital data to the monitor.

An RGB monitor consists of a vacuum tube with three electron guns -- one each for red, green, and blue -- at one end and the screen at the other end. The three electron guns fire electrons at the screen, which contains a phosphorous coating. When the phosphors are excited by the electron beams, they glow. Depending on which beam excites them, they glow either red, green, or blue. Ideally, the three beams should converge for each point on the screen so that each pixel is a combination of the three colors.

Actually each pixel on the screen is made of three phosphor dots each made of a different phosphor type ( red-emitting, green-emitting, and blue-emitting phosphor ). So the three beams MUST NEVER CONVERGE, if they do converge they would only hit one of the phosphors and the pixel would only have the color of that phosphor. Between the glass and the human brain the 3 color dots are combined into a single pixel.

Also since all three electron beams originate from different locations and are all deflected by the same set of coils they cannot converge, if they needed to converge then CRTs would have to be constructed different so that each beam has it's own set of coils and the logic to drive them would be much more complex.