Display contains garbled, multicolor lines

I'm having the same problem with my PowerBook Aluminum 17". I tried tapping on the top pf the LCD screen and it seems to help. Then I took off the back cover and re-seated the display cable..no help. Then i removed and re-seated the inverter cables .. still no help. Now I just found that by squeezing the display in the upper left corner, it comes back on okay! So, do I need to take the protective tape off the connectors on the LCD panel and try to reseat those connectors. or am I looking at a new display?