Help! My screen won't work!

I recently got an old Macintosh Powerbook 140. I have plugged it in, and when I power it on, I hear the startup sound, and the speakers emit a tone, but the screen displays nothing. I have checked for any visible damage, and there appears to be none. It may be of note that the computer hasn't been used at all for the past 20 years. I do know that the last report of its use was that the screen was a bit touchy. 20 years ago, the screen could only be seen from the correct angle, but now there is nothing. Can anyone help?

I should also note that I have little experience with physical electronics. I work well with technical stuff, but I only have a basic understanding of electronic terms. If you could explain and terms for me, that would be great. I can do some work with electronic components, but I don't trust myself with big overhaul or too much soldering. If you have any solutions that require little or no of said things, that would be great.