Hi, I have compaq 7540 monitor 17''. It is showing only part of the screen and when I shake the monitor or plug it displays full screen for a second and gets reverted. Please help on this issue.

It could be EMI by the monitor, or it could just be failing. Try the following.
1. Do you have speakers or other electromagnetic sources (walkie-talkie, cell phones, etc.) sitting close to the monitor? If so, try moving them away from the monitor. They will effect how the electrons from the electron guns hit the color phosphors inside the monitor tube making the display blurry.
2. Try running a monitor diagnostic to check if the monitor is finally failing.
Post back how it works out.

You could try this link, but it would be far cheaper to upgrade to a new or second user LED/LCD monitor
http://www.eserviceinfo.com/index.php?what=search2&searchstring=schematics+diagrams+hp+7540+crt+monitor

It would be more economical to purchase a new or used LED/LCD display rather than wasting money on an old CRT monitor.

Sounds like your CRT is dying. Sometimes older ones can take longer to turn on, I would suggest upgrading to an economy LCD, they're pretty cheap.

change the monitor front panel menu control switches. (All 4 Switches)

Hi Kartik,

• You did not mention your Operating System (OS) in the question.
• But still you can do it by following the link.
• From the page choose your troubleshoot manual depending on your OS

-rate the post if it helped.

reboot the system by pressing F8 if your using windows OS and select last good configuration.

you can try also selecting Enable VGA mode (press F8 while rebooting and select ENABLE VGA mode).

hope this helps, please rate.

You bring to technical personnel to fix it for you .

check the pin # 1 of video input cable { broken or Bent }
if it is ok then there must be a problem with the cable or RGB Processing Circuit { Normally Dry Soldering of a faulty IC in the circuit of CRT BASE} .

Your button is stuck. If it is stuck on the external button, try plying it forward with a needle, if it is broken internally, a technician can fix the switch on the board for you.