I cannot figure out what is wrong. I need help.
It's a Powerbook G4 12 in 867Mhz (Aluminum)
these are the symptoms:
when I power up I hear the chime but the screen is blank.
Same thing if I power up using just the battery and/or power adapter.
Connected to an external display. Nothing.
Tried to start in Target mode. Nothing.
The light on the power adapter connector is on.

Looking at the symptoms I decided to replace the logic board.
After replacing the board symptoms are exactly the same.
What are my other options?
shall I replace the DC-DC board or it's a wast of time/money?
I really don't know what else to do.
Any suggestion would be very appreciated.
thank you in advance.
G

typically the issue you described would be the logic board as you suspected, but if a new board does the same thing that is quite weird. Generally on that model if the screen goes out, it ends up being the LCD itself, but if it doesn't work on an external, that most likely won't be true. For the DC-DC board, the machine usually won't turn on at all if it is bad. If you are wanting to fix it yourself, I would probably go with the DC-DC board next, but I'd really recommend taking it somewhere to get diagnosed at this point so they can switch out all the possible parts without you having to keep ordering them yourself and sending them back.

we do offer a free diagnosis here if you don't mind shipping it off, and if you decide for us to not fix it, you'll only be required to pay the shipping costs.