Dimension 4500S

Hi lidio7, I would like you to click the link below & scroll down till you see Diagnostic Codes. Please follow the instructions listed.

http://support.dell.com/support/edocs/systems/dim4500s/advanced.htm#1118998

In your post above you mentioned all the lights in the back of computer are all ok!
Does that mean you are seeing all four light ( A, B, C, & D ) show solid green?

Please varify the colors of the four lights. I suspect light A is yellow, B is green, C is yellow & D is green.
Double check the monitor cable. Make sure it is connected & tight at both ends (PC & monitor). If all lights are green can you possibly connect a different monitor? Any VGA monitor will do.
If you can connect another monitor & your video display returns you have a problem the your monitor.
Please check all of the above & post back here as a follow up.
Scroll down a bit more to Beep Codes.

If the monitor cannot display errors or problems, during POST the computer might emit a series of beeps, or beep code, that identifies the problem. Pay close attention for these beeps.

Try all of the above & let me know your findings. We can go from there.

Thank you for your time.
map9966

hi!,
I hav a solution 4 u . Ur LCD monitor's wires of ur Laptop Has gone loose , U can just give ur lappy 4 a servicing.
byeee........