Toshiba L350D Screen Loss

You may plug off remote monitor power on to see carefully is there normal dark picture on your lcd screen,
!) lcd dark but there is pcture on the screen, it means the back lights inverter damage(which in the lcd lid and downside of lcd panel), or lamp damage (in the lcd panel), have to replace new parts
2) no any picture and dark panel, you may check lcd signal cable plugs are right seat in the sockets (which located between the back of lcd panel and motherboard), also check the inverter cable same thing (it merges in LCD cable) . it is better replace a new cable (most cases are cable disconnection somewhere)
is this helpful please feedback when you checked, iwill tell you what you can do next, thanks