Key commands before startup won't work!

I just got a new Mac Pro Quad-core (early 2009) and want to move files from my old G4 Quicksilver to the new machine using Migration Assistant. Connected firewire cable and restarted G4 with "t" key pressed to put G4 into target mode, per instructions. G4 powers up but I get a black screen. Same happened last week when I pressed "option" key to choose a different startup disk. Same when I press "c" at startup to use cd to bootup, 'a blackscreen'!

Question #1: What's wrong with the G4? Pre-boot up key commands don't work!
Question #2: How can I get my files from the old Mac to the new Mac?
Question #3: I do have a fully backed up HD in the G4 and an external fully backed up HD with firewire connection for the G4. Is there a way of using Migration Assistant, via firewire, to utilize the external backup of the G4 to load the new Mac Pro?

Or whatever you think will work.
All suggestions will be entertained.
Thanks in advance, Jim.

Not sure but i always hit the power button then press the T key - is that what u are doing?

I don't believe you can boot a PPC-based Mac from an Intel machine, period. The operating system simply won't run.

When you boot the Mac Pro, does it not mount the disk(s) from the G4?