ibook g3 blinking and freezing screen

[jussMacNit]

when I'm using my ibook it sometimes blink and then goes blank/black and I have 2 shut it of manually and then when I boot back up I hear the chime but get nothing but a black screen

 

[DeltaMac]

That's a very typical failure for an iBook G3. Apple had a repair program to fix those some years ago, but that is long expired. The logic board has an on-board connector or the graphics chip which begins to lift off the board (losing the connection - especially due to heat). There are companies that repair that problem. You would have to decide if the investment (2 or 300 dollars) is worth it for you.