display, cable or something else?

[errlizabeth]

hi, i have a desktop with benq monitor, several years old. when i start the pc the monitor shows the usual startup for a few seconds and then reports no signal. i had issues a few days prior to this where monitor would be covered in white rectangles randomly distributed. i have tried to connect my laptop to the same monitor, and its the same- shows windows startup then goes blank and reports no signal.
when i turn on the monitor, when it's not connected to either the pc or laptop, it shows benq purple screen ok, and then reports no signal.
i tried to connect the pc to the laptop, but as my knowledge is limited this didnt work out for me - tried something with display settings where i have chosen between 1 and 2 displays etc, but i can only guess that i didnt do it right. the pc never appeared on my laptop screen.
also, i have opened the pc and checked that everything is plugged in ok, removed small bits of dust, but there wasnt much.
my pc has a graphic card, few years old, cant remember the make i think n-vidia- at the time of purchase it was top-spec as i do graphic work
ventilator works ok

is there a way to fix this or at least to find out whether the problem is the graphic card, the cable or the pc (motherboard, or even ram as i see some people suggest removing ram n plugging it back)

many thanks!

 

[ss202sl]

Is there a button to select input for the monitor? Is it set to the right input (sometimes my son will hit this button, and my monitor will do the same thing).

Using you laptop helps narrow it down to either the monitor or cable since neither the PC or Laptop displays on the monitor. Can find another cable to try? Can you try a different monitor?

 

[hang-the-9]

You can't hook up the computer to a laptop, the laptop video is output only. Follow advice above and try a different monitor or cable. I'm sure you know someone who's monitor/cable you can borrow for a few minutes.