Ok, thanks for the reply.
First things first, the cables. If the cable from the monitor to the pc cant come off as its part of the monitor, fine, they are usually good ones anyway. The other cable, from monitor to the wall, if you have a spare around it wont hurt to change that, but i doubt thats the problem to be honest about it.
At this point the best thing to do is borrow a monitor from someone and see if the same thing happens to that monitor. If the same thing happens with the borrowed monitor then we pretty well know you have a power supply problem. If all is well then we know your monitor needs repair or replacement.
If you cant get hold of another monitor via a friend, you could try buying a cheap 14 or 15 in used one as a backup and try that. Again, if another monitor works fine then you
know the power supply is the likely culprit. Or, as I have suggested above, you can get a multimeter and test your power supply.
This is all a lot of work and effort on your part but you dont have a lot of choices. There is one other, you can call a shop that repairs monitors and tell them the problem, they might be able to tell you right away if its the monitor or not, worth a phone call anyway.
Yes, inside each pc is a motherboard with things attached like fans, cpu, hard drives, etc. Also attached to the motherboard, often at or near the top, is the power supply.
The power supply has at least one connector to the motherboard, a white end thats thin and long, 20 wires on it, its the only item that has 20 wires, so you cant miss it, follow the wires to the power supply! If you have a P4 cpu then you will have an additional 4 pin connector from the motherboard to the power supply, 2 yellow and 2 black wires, 4 in total. If you have a P3 or amd cpu then you wont have that 4 pin connector. Some mobos even have another 4 pin connector that is a standard 12 volt, the same as you plug into a hard drive, yours may or may not be like that but all motherboards have the 20 pin for sure!
A UPS is an uninterruptible power source or power supply, different from the one inside your computer. What happens is this. The power from the house or office is in the wall and you connect to it at a plug. A UPS plugs in there and then you plug your computer into the UPS. A UPS cleans up the power at the wall and makes it much more compatible to the needs of modern computers. The power in our walls was not built to handle computers as you can well imagine. Now a surge suppressor is a different thing. You can think of it as a cheap, mickey-mouse imitation of a UPS. A UPS not only gives you clean power at the wall, but it also has a good quality surge suppressor built into it, and it has a battery so that if the power goes out for a part or a second, which can ruin a computer, your computer still has power as its stored in the battery and can re-act in a very small part of a second!! And a UPS protects against power losses and power surges, both of which are death to computers and even monitors and printers too. If you have a UPS you dont need a surge suppressor, but if you only have a surge suppressor, you have only a bit better than nothing. And some surge protectors are much better than others, some are totally useless anyway. Even the best surge suppressor can only partly protect a computer and its parts while a UPS does the whole job. UPS are worth their cost and then some and i would never be without one and there are plenty here who would agree.
The point is that whatever is the problem with your monitor you should still have a UPS hooked up to your computer and monitor anyway, but it wont fix a broken monitor of course.
So first things first, i guess. Lets find out if the monitor is broken or not, right?
Getting back to the power supply. Since you have basically stated you dont know what the power supply looks like, its likely you are dealing with a now 5 yr old cheap power supply and it could very well be failing, but personally i think your monitor is failing. I am only saying it could be the monitor or the power supply, but i do think its the monitor, even if its only 5 yrs old, i have one go after 4 yrs! But you need to find out.
Good advice + great people = tek-tips