Q: Powerbook G3 Display Issue

Dear Forum Mac Guru's,

I know this has been asked a few times before but I thought all the comments I've read so far have not been quite my situation. So here I go...

I was wondering if you are able to help
diagnose a problem I am having with my Pismo Powerbook?

The LCD still has a good crisp colour to it with no dead pixels or dim
spots or bright spots. That is until things start to go wrong. If I leave
the powerbook off and turn it back on again the LCD is fine for a while.
Then it will start to flicker with horizontal white lines in random places
every time. The image that was last on the display freezes and eventually
the flikering lines will become solid and the white will wash away any
image that had previously been there. eventually this white will go a dull
grey colour. This will all happen very quickly. In a matter of about 30
seconds.

Initially it was only intermitant and would go away by pressing the back
of the screen or pushing down on the screen (down dosen't help all that often). This however rarely helps these days.

I initially thought it was the Inverter board but then came to the
conclusion it might be the display cable. After replacing the display
cable (making sure it was the same brand screen) it still started to
flicker and the same things happens.

I have been running an external display for the past year with this problem and the external display runs without an issue. When the laptop display gose blank the external display runs perfectly.

I did a number of test on the computer when the display gose funny. I tried to push pod and poke the main body of the computer but this has no affect on the problem at all. The backlight is not an issue, it remains on. The screen has a number of vertical lines that appear once its grey (these may be there straight away but don't become apparent until the screen is greyish). I have leff the screen in the greyish state for a while and generally a couple of white lines will remain and randomly flicker every now and again. The screen in this state sometimes seems to dim in light intensity, this comes in and out. If the machine has been off for a little while (off not sleep) then the screen generally will last alot longer before going to the bad state. Moving the screen from almost closed to almost open the screen can go to the faded state at any position but will generally change as the screen is moved. The screen is best I feel when the screen is in the full extension open. When the screen dims (properly whilst saving power) it dims correctly but just makes the greyish look darker. If i touch the screen in the right spot it will spring back to life and be as crisp as it ever was. It also seems to have a darker rectangle in the centre of the greyish area. I think that is all?

Other than this problem recently the computers battery died and has been replaced and the cd/dvd drive has been replced. The screen problem was happening before these became and issue though.

Would you have any ideas? Also any suggestions on parts to fix it with?

Thanks in Advance, Tre.