Movement of my desk caused the monitor (XG-91D) to lose some of the colors. The screen only displays greens, blue, brown, gray and black tones. Readjusting the screen temporarily helped but it goes out again. Cables have been jiggled, tightened and the angle of the screen moved. This does not correct the problem.

Try hooking the monitor up to another computer or laptop, do you get the same results?

Try this link:


Xerox XG 91D 19 in Flat Panel LCD Monitor

Try this link:

White screen on xerox xa7 19i

Hello! There are two sensors that will cause this problem both can be tested...If you have a volt meter...If not, let me know...
#1 is the Throttle Positioning Sensor (TPS)...A black round device that is bolted to the throttle body with a three wire connector...Wire colors are...Gray/White...Brown/White...And Gray/Red...Using two safety pins plug them into the rear of the in place connector on the Gray/White...And Brown/White...Place + probe of meter set to read 5 volts on the Gray/White...And - probe on Brown/White...Start engine...At idle must read less than 1 volt (.85)...As you slowly increase throttle meter must rise smoothly to 4 volts at open throttle...If voltage jumps or acts erratic the sensor is defective...

#2 is the Manifold Absolute Pressure (MAP) sensor...Also mounted to throttle body...Three wire connector with the following wire colors...Light Green/Blue...Gray/Red...And Brown/White...Using the same technique...Pin the rear of the connector on the Light Green/Blue...And the Brown/White...Place + probe on Light Green/Blue and - probe on Brown/White...Turn key to on (don't start)...Record reading...Move Light Green/Blue probe with safety pin and push it into the Gray/Red wire...Record reading....Also check the vacuum line which is connected to the Map Send results...

Cost...TPS=$55............MAP=$95

Guru.................Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

It's most likely a locking point to fit a Kensington type security system to lock the monitor to the desk.
Does anything happen at all when you switch it on?

First place to look will be the power supply section, look for bad caps (bulging tops or bottom seals), the post back what you see so we can guide you further for direction such as voltage checking, see example of failed monitors due to bead caps: http://s807.photobucket.com/home/budm/allalbums

my desk top is half display is ok and half display is white light & all program is look a lite

If you look on the back of the monitor it has the name of the manufacturer - which I googled and found this warranty information: http://www.sylvania-displays.com/Support/warranty.html

If you already know that your monitor is out of warranty but want to try to figure out what's wrong with it, these are the contact numbers:
California:
PTI
7373 Hunt Avenue
Garden Grove, Ca 92841
Phone: 714-799-3899
Fax: 714-379-6290
Hours: 8AM to 6PM Pacific Time
Texas:
PTI
10849 Kinghurst Suite # 120
Houston, TX 77099
(281) 530-4100
(281) 530-4104 fax
Hours: 8AM to 6PM Central Time
For further warranty information, please contact our Customer Service Department
Call our toll-free service number at 1-800-776 8439 for out-of-warranty service rates.

Did you have another monitor to verify the problem whether it is related with the Video card or the monitor itself?

Hello Frank, I have the same problem with my monitor. I don?t have the answer yet to resolve the problem. if you want the first of us who find the resolution will advise the other. I sent an email to Xerox to get the info to remove the cover without breaking it. regards Sylvain