Compaq M2305NR Display Problem

I was having a problem with a thin vertical blue line appearing on the
display. So I took the laptop apart several times trying to fix it to
no avail. Last time I put the display back together, all of a sudden
the computer won't even startup. I get the power light for about 2
seconds and then nothing, no fan noise, no drive noise. Any ideas
what to try to fix this. I am ordering a video display cable on EBAY
first to try that.