This is a long post- but please bear with me - its a case of multiple organ failure!
After being dropped by my dear son, my old powerbook Ti 667GHz DVI 15inch mac was seriously injured; the left display hinge broken. The loosely attached display no longer worked - it lit up uniformly accross the screen but displayed no data. Still he continued to use it quite satisfactorily with an external monitor.
I assumed the problem was probably damage to the data cable to the display and last week I picked a replacement display off ebay and left hinge which I carefully glued into the display and then swapped the old display for the new one. This now has two happy hinges, but still exhibits exactly the same problem - the display lights up but nothing appears on it. I have seen previous threads on this, so would add that there is absolutely no graphics visible, even when I shine a light through the display case, but as I said the backlight still works fine and goes brighter and dimmner when the screen brightness buttons are pressed.
Before giving up on this as being a logic board problem, has anyone any suggestions as to what else may have been damaged in the original dropping of the powerbook? Could this be a problem at the cable connectors on the logic board? There are 3 cable connectors going from the logic board to the display, the one on the right I think is the inverter, the multicable on the left data? what is the second connector on the right?

There is a second part to this posting - you may wonder why I am so keen to replace the display if the powerbook has been working fine on external monitor-- the reason is that recently it developed another fault - it would no longer recognise blank CD-Rs for burning. The drive reads CDs and DVDs fine, just won't accept blanks to burn. Exactly the same happens with a USB external CD-R drive. Also I don't seem to be able to view the hard disk in firewire target mode from my other mac. Makes me think the system is corrupted. Here's the problem. If I want to reinstall the system from my original panther installation CDs, when the computer boots up on the installer disk, the external monitor no longer works! Presumably the installer OS on the CD doesn't have the drivers for video mirroring. So I am stuck. As I can't use the powerbook displays, I can't do a clean reinstall of the system, so can't try to fix the CD burning problem. Now you see why I tried a new monitor! So any good ideas about how restore the parts of the system that might allow CD burning would be welcome.
Jerry, Aberdeen, Scotland