Hi Bruce, there might be 4 different reasons for the backlight not working: 1. Worst case: The fluorescent light within the display broke. It is a 3mm thick glass tube which is located below the LCD screen across its whole width. Very tricky to replace. Can be done, but you will have to open the display assembly with its glued seems and you will have a hard time to put it all back together properly. Easiest would be to replace the display as a whole. 2. Most simple case: A wire disconnected due to the shock of the impact. Either the ribbon cable that goes from the logic board to the inverter or the AC cable that goes from the inverter to the display. 3. The AC inverter cable ripped. This usually happens when a hinge is broken. This is the most obvious reason. If your hinges are intact, the cable is probably ok. 4. The inverter is broken. It is pretty unlikely that this happens due to a drop because it is a little electronic circuit board which is quite resistant to mechanical impact.
Here is what I would do: Try a PMU reset first. Maybe it is a corrupted sleep logic. Unlikely if the Tibook was shut off when it dropped - but you never know. If that does not help, set the brightness to lowest setting, which is OFF, shut the display and let it go to sleep, wait a couple of seconds, open the display again and hit the brightness key (brighter) once. If the backlight comes on with lowest setting, and goes off at a higher setting it´s a bad inverter. If there is no light at all, look for disconnected cable: Open the back of the Tibook. Check the inverter cables properly connected. The DVI models have the inverter located in the lower left corner (TiBook upside down, hinges facing away from you.) On earlier models (400/500/550 and early 667MHz models) you have to remove the optical drive to get to the inverter. If the cables are all properly connected your attempt to diagnose probably ends here. If you have a couple of disassembled Tibooks in your workshop like I have, you could start swapping parts. Inverter first, then another display. If you need assistance with some details, let me know. IFIXIT also has excellent guides on their website (http://www.ifixit.com/Device/PowerBook_G4_Titanium_Series) Replacing an inverter or a display is easily doable if you have some technical skills and the proper TORX screwdrivers. Best Roland Am 18.06.2012 um 08:29 schrieb Bruce Ryan: > Hi folks > > On the way to visit my parents last week, I dropped my TiBook while I was > trying to put him in his protective sleeve. Since then, his screen has been > dark but I could just make out the outline of the login window if I > force-restarted him. > > Now I’m back home, I can verify he appears in screen-sharing and works just > as ever (see http://bruceryan.dontexist.net/202012/06June/TiBook.jpg) but > still has a dark display. > > I guess I killed the backlight but could there be other causes? > > Also, how much of a pain is it to source and replace the backlight. (I’m in > the UK.) > > thanks muchly > > Bruce > > -- > You received this message because you are a member of G-Books, a group for > those using G3 iBooks and PowerBooks (we run a separate list for G4 'Books). > The list FAQ is at http://lowendmac.com/lists/g-books.html and our netiquette > guide is at http://www.lowendmac.com/lists/netiquette.shtml > To post to this group, send email to [email protected] > To leave this group, send email to [email protected] > For more options, visit this group at http://groups.google.com/group/g-books > > Support for older Macs: http://lowendmac.com/services/ -- You received this message because you are a member of G-Books, a group for those using G3 iBooks and PowerBooks (we run a separate list for G4 'Books). The list FAQ is at http://lowendmac.com/lists/g-books.html and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To leave this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g-books Support for older Macs: http://lowendmac.com/services/
