Monitor turns on but screen is white

Look for the power button/switch on the monitor

Disconnect it from computer and power. wait 15 minutes and plug only the power back in, press the power on button. The monitor may display a message that there is no signal or something like that. If that happens the problem is either the cable or the computer. If you get no message then look for the menu button and press it to see if any thing appears. If not find the manual on line and read it. Many times monitors get over-driven by computers to the point that they can't display OR they self destruct.


OR

Another way is to just unplug everything computer and monitor for 15 minutes. Plug in monitor first then plug in computer and press the power button, the display should display the booting information if the cable is good and the monitor is good.

Troubleshoot an HP LCD Monitor
HP makes a number of liquid crystal display, or LCD, monitors.
LCD monitors create an image by passing light through a liquid crystal solution that either blocks the light or allows it to pass through to a color filter.
LCD monitors are ideal for use with a computer as they present an excellent still image and cannot suffer pixel burn-in like other flat-screen display technologies.
Even quality monitors run into the occasional problem and need some basic troubleshooting before sending them in for service.
Check the power cord to make sure that it is plugged in securely to both the monitor and the outlet. If you are using a surge protector, remove it and plug the power cord directly into an outlet that you know is working.
Detach and reattach both ends of the cable running from your computer to your monitor.
If your HP LCD monitor has more than one connector, use the other one to make sure that the connector isn't the issue.
Remove any switch or extension cable that may be present between the computer and the monitor.


Restart your computer. A fresh start will correct many software issues.


Check the documentation of your video card to make sure that it supports HDCP, or High Bandwidth Digital Content Protection, since the screen may be blank when you are trying to watch high-definition content through a video card that doesn't support it.
Some older HP LCD monitors also do not support HDCP, so check your monitor documentation as well.


Go to your video card manufacturer's website and install the latest drivers for your video card. Instructions for installing the drivers will vary by manufacturer, but they should be listed with the driver software.


Change your resolution to a preset video mode to make sure that you aren't trying to operate the monitor in an unsupported resolution.
Different models of HP LCD monitors support different preset video modes.
All of the preset video modes for your monitor are listed in your monitor's manual.
Resolutions of 1024 x 768 and lower are supported by almost all HP LCD monitors.


Press the "Auto/Select" button on the front of the HP LCD monitor to correct any images that are dark or blurry.
If this does not correct the image, press the "Menu" button on the front of the monitor to bring up the on-screen display menu, where you can use the "+" and "-" buttons to scroll through the options and "Enter" to select the option that you want to change.
Adjust the brightness and contrast as needed by selecting them and using the "+" and "-" keys. Press the "Menu" button to exit the menu.


Press the "Menu" button to enter the menu, scroll to "Image Control" and press "Enter."
From here you can choose the "Auto-Adjustment" option and the HP LCD monitor will automatically adjust the horizontal and vertical positioning to center the screen.
The ability to adjust these settings is available only if you are using VGA inputs.


Contact your retailer or manufacturer for any additional troubleshooting steps for your particular model of HP LCD monitor.
If your monitor still has issues, you may need to send it in to be serviced.
HP Support

http://welcome.hp.com/country/us/en/support.html

Fix a White Screen on an LCD Monitor
When an LCD screen has turned completely white, there are three normal causes: the screen is defective, the video cable is not connected correctly, or the graphics card on the motherboard of the computer is faulty.
You will need to troubleshoot these possibilities to determine which problem you have.
If you are not experienced in working on computer equipment, you should not attempt to disassemble your LCD screen because you could easily damage it.
Seek professional assistance unless you have experience working on computer hardware.

Disconnect the white LCD screen from the computer by unscrewing the blue monitor cable. Connect the working LCD screen to your computer by attaching its blue monitor cable to the same slot.
If your computer display does not show on the functioning LCD screen, try rebooting your computer.
If it still does not display, the problem is with your computer's graphic card on the motherboard. Seek professional repair assistance.
If your computer display shows normally on the working LCD screen, proceed to Step 2.
Unplug the LCD monitor with the white screen.
Disassemble the rear panel of the monitor with the small screwdriver.
Carefully separate the screws into piles so that you can keep track of how to reassemble the monitor.

Locate the internal video cable, a gray cable with a plug on the end that connects to the main components of the screen.
See the References section for photos of the video cable for assistance.
http://www.laptoprepair101.com/laptop/2008/04/13/laptop-lcd-screen-turned-white/
Unplug the cable, checking for any debris or blockage.
Reconnect the cable firmly.
Reassemble the LCD screen. Plug it in and connect it to your computer.
If the screen is still white, you have a defective LCD screen.
You will need to replace it or take it to a professional repair service for assistance.




Without this test you'll have to guess because as I mentioned before this could either bad motherboard or bad LCD screen.
You'll have to disconnect the video cable from the LCD screen (connector 2) and the inverter board (connectors 3 and 1).
After that you connect another working screen and test video.
For this purpose I'm using one of my test LCD screens.
My test screen is cracked and because of that you see a wide white band in the center but it still works fine for this test.
The original screen is white but my test screen works normal (except the crack of course) and I can see the image.

After this test I can tell that the problem must be related to the screen.
After I assembled everything back together and connected the original LCD, it's still white.
CONCLUSION. In my case this problem is related to the LCD screen and it has to be replaced.

WELL GEE WIZE THE OLD MONITORS CCLF LAMPS ARE DEAD
IF THE OSD MENU BUTTON FAILS EVEN NO XBOX THERE
IF AT POWER ON MON, UNDER 15 SECONDS COUNT
THE OSD MENU KEY IS DEAD THE MONITOR IS BAD
IF MONITOR FAILS ON A REAL; pc IT IS DEAD. OR 2ND PC.
IF FLASH LIGHT POINTED TO LCD SHOWS DATA THE CCLF ARE DEAD. AS ALL ARE NOW. RIP JUNK GRADE OLD CCLF MONITORS. 20,000 HOURS AND KAPUT.
IF GOOD IS ONLY
1280 x 1024 JUNK AGAIN GRADE.
OR WRONG MONITOR POWER PACK OR BAD. OR WEAK

x2 test monitor on other pc.
if its ok we fix pC>
if the pc drops the sync lines H/V the monitor goes to sleep mode.
and tells you that.
the old monitors 2004 have timer inside,
does the OSD menu button on front of monitor work
with PC on,? it must.
OSD = on screed display from monitor brain
if yes, makes sure any menu there has the sleep timer off.
if it has it.
this monitor is old older than 2010. and has CCFL backlamps then and older.
so use flash light to see if data is on the screen if yes.
then the CCFL tubes are bad or the HV card inside dead.

yup your your service manaual
advanced OSD page clearly show the power saver clock
turn it off now.
of you cant get the OSD to work find a good PC
plug it in and turn this off below.


sevice manual google is your friend, sometimes.

see if you have bent pins on cable.

try it on 2 PCs or just 1?, be wise to do both . no?
it takes computer to make the monitor work
sync signals on 2 pins. horz/.vertical/.
then the monitor menu key will show the OSD screen
if not it's dead.
the CCFL tubes fail first (they are short lived ! unlike a LED monitor from 2010 to now, why not upgrade.?
its 18 years old, now, do you expect CCFL tubes to last that long?
1999 it was made.
here is the manual
it tells you all steps to diagnose it
but the magic test, called the flash light test.

https://www.manualslib.com/manual/1228058/Compaq-P1100.html?page=4#manual

flash light test,
http://www.pcdied.com/monitors.html#flashlighttest

when i turn the computer on the light on the monitor blinks green but i cant get it to turn on..i have a black screen.

Unplug the power cord for the monitor for a few minutes

your monitor is telling you it's on it's last legs..either that or your compaq has a bad video section. either is more vital than a video cable being loose.