White screen after about 20 minutes of operation

SOURCE: Screen color changes, white becomes yellow.

I think you need to clean your monitor inside of it, dust can conduct heat making the screen material active and creating the yellowish tint to the screen.

I don't think it's a connection problem, becuse it if was you would not see nothing on the screen at all but only one connection error message or like 3 colors.

so you have to open it and clean it I usally use a hair dryer to clean inside stuff or a paint brush.

try cleaning it, but if you have special screws that you have to take out from the monitor you then have to buy special tools for those screws.
I had the same problem right now with my monitor, it's 7 years old, and decided to get a dell flat screen 22 inch.
but that's what I think is your problem, it's either dusty or oxidized meaning different oils are layered inside on the circuit boards. which are like insulators

SOURCE: Going to Sleep

got the same issue

hp pavilion 1723

SOURCE: Going to Sleep

Due to the power surge, it is highly possible that the monitor was given a boot by your computer on it's way out.

This will short out a very small transistor inside the monitor on the video board and in turn, then monitor cannot see that there is a signal so goes to sleep.

If you get brave enough to venture inside the screen, then check near the cable input. The transistors are only around 3mm and have 3 legs (two one side and one in the middle on the other).

If you find anything like that burnt (get a magnifying glass) then replacing the board is the easiest option. Just don't be tempted to wipe the board before you look at everything very closely, you may wipe away the tiny bit of evidence you are looking for.

Hope it helps =)

SOURCE: After hooking up this monitor,the 1702 goes

Hi Don,
it sounds like your monitor's Capacitors have gone bad. This is very common. It is repairable, but the caps have to be removed and new ones resoldered on.

If you have soldering skills, not too tough of a job. If not, a shop will usually charge around $100 or so. You will have to weigh the cost vs a new monitor on this one.

Here is some more info for you on the Capacitor plague, that is quite common on monitors now.

http://en.wikipedia.org/wiki/Capacitor_plague

SOURCE: Screen goes black but still can see the desktop??

It sounds like you are losing the backlight....the backlight is what lights up the panel. The inverter takes the signal from the motherboard and sends it to the backlight. I would change both out. The inverter is usually a seperate component....the backlight is built into the frame of the LCD...it can be changed, and there is a guide for that but most LCDs come with a backlight built into them. Below is a guide for backlight replacement.....

http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/