HP 7540 crt monitor shrinks to a horizontal line

Try a different CRT monitor on your computer.
Try your CRT monitor on a different computer.
See if the problem "moves" to the other computer,
or whether your computer has problems with *ANY* monitor.

it is repairable but for the cost of parts and labor you would be better of getting a new 22" LCD monitor
for the problem I would suspect the fly-back transformer or power supply

thanks for rating

<div style="FONT-SIZE: 14px; PADDING-TOP: 10px" itxtvisited="1"><span id="ctl00_ctl00_MainColumn_CenterColumn_ThreadBox1_lblProblem" itxtvisited="1">my hp 7540 crt monitor menu displays automatically blinks frequently. please hele me resolve this problem. it stays fixed on the screen, unable to do any work.</span> </div><!-- answer --><!-- from fixya rte -->

Try repairing your monitors cable.

If you mean 'flyback' or 'horizontal output transformer' and have the part number available, try one of the sources here:
Flyback links 
If you do not have the number you may have to search Viewsonic's website to loacte it.
Warning; the number of suppliers for CRT monitor parts is shrinking rapidly, my best supplier, ICM in California is long gone. 

Hi...there,
Open your on-screen display on your monitor, find & press auto adjust. If that doesn't work go to factory reset menu and pressed to reset to original settings.Then reboot your pc.

click the menu butten on your monitor and click positioning and they it should be under horizontal and vertical but if its on the sides click horizontal and use the plus and minus buttens on your monitor to adjust it.

Im not too sure on how to fix the ungrounded curcit but upgradeing to a lCD panel would completly fix this problem.

You need to service your monitor. Give it to an authorized service center.

burn your monitor