Attempting to initialize target disc mode


im currently attempting to connect a macbook with a broken LCD screen to my other working macbook & access the one w the broken screen via target disc mode. i purchased a thunderbolt cable and am able to connect the two computers, but the problem im having is that when i try to shut off the mac with the broken screen in order to start it back up in target disc mode, it appears as if it's refusing to shut down. i tried holding down the power button, and also tried holding down the power button whilst holding down the command & control button, but after letting go of the power button, waiting for a bit & then pressing the power button again to see if the computer has turned off & will turn back on again, the screen lights back up but i dont hear the chime of the mac starting up, implying that it never successfully shut down. ive been waiting for the battery to run itself out for two days now but every time i touch the power button briefly the screen lights right back up with no startup chime. i need to access the files urgently. any help would be highly appreciated, thank you
Try this:
On your broken screen Macbook: Hold the left side Shift, Control, and Option keys, then press and hold the power button for 10 seconds.
Release all keys.
That is an SMC reset, and (assuming the keyboard is working) absolutely will reset your MacBook, and leave it powered off, until you choose to power up again.

If you want to reset completely, you can also do an NVRAM reset (also known as a PRAM reset).
From power off, Press and release the power button, and immediately press and hold Option, Command, P and R keys.
Continue to hold the keys. In a few seconds you should hear the boot chime. If you don't hear the boot chime, you still should hear the optical drive make a bit of noise while it resets.
Continue to hold the same 4 keys. You should then hear the boot chime this time (or at least the optical drive will reset again)
Keep holding those 4 keys for one more reset cycle. You SHOULD hear the boot chime by now. Release the keys...
You can do that SMC reset again, to force it off.

Now, to set up target disk mode: On your broken-screen Macbook -- Press and release the power button, and immediately hold the "T" key.
If the screen lights up, you should see a Firewire icon (I call it a "dog-face (see the ears?), which will float across the screen.
And, connecting the Firewire between the two Macbooks, will make the broken screen drive accessible on the desktop of the good Macbook.