Black screen on boot but chime sounds

I would bet money you have a in-line p link fuse or the WLED driver which is a QFN chip blown. Your going to need to need some real expertise to test the QFN chip with very fine probe tips to test it and there is a possibility of shorting the board cause the contacts are so close. Me personally? I would change them both but soldering a QFN is extremely hard youtube QFN and you can see what i'm talking about.

Are you using the external monitor correctly in clam shell mode?

Try this first , put the installation dvd. Power it on without pressing anything any key commands , immediatly close the lid when it fires up and plug in the external monitor wait with the lid closed unitl the installation dvd comes up. If all goes good you will be able to use your mac and at least know it works , but this will tell you if you your screen or video cable or backlight or backlight fuse is bad. Then on to the next!

You could also shine a light into the middle of the screen and look for the blinking folder icon, that would indicate the backlight is not working. If it is an MC207 model, it is a LED-backlit screen and will need to replace the whole screen.

As I understand it that is a problem with the GPU and reballing the solder underneath will fix it. There are plenty of repair places you can send it to for 100-125ish to fix it. This is not something that would be able to be done at home with normal tools. I have also seen a temporary fix of using a heat gun to attempt to resolder broken points, but its only a temporary fix when it does work, and most of the time it does not.

I have same problem. My Macbook A1342 Late 2009 turned on but the screen is black. I can see everything on desktop with a flash light. My story are following:

The old screen is freezing at some point when starting up. I have to fold/move the screen a bit to get it fully started up. So i thought it is LVDS cable

I tried to replace LVDS but nothing changed. My bad when i tried to connect wrong end of LVDS. Then my old screen is gone. Nothing show up on screen even with a flash light. It still turned on, took installer disc and made sound like it reading the disc.

Now it ordered a brand new lcd screen panel. It turned on but black screen. I can see everything on desktop with a flashlight.

I did not see apple logo on back of screen light up.

Do you know how to fix it?

I had a similar issue. My macbook crashed, nothing would restart it. I did the NVRAM reset multiple times, it seemed like it did not work, though I could hear the chime on startup and when i would fiddle with the volume control would hear the "pluck pluck pluck" sound. Then I shut the notebook, reopened it and VOILA it worked! Was so thrilled, I thought this Macbook had bitten the dust!