My ibook G4 is messed, this is my last hope.

12inch ibook G4, 800mhz, additional 1gig third party ram.
neye:

So, I 've had this problem off and on for about two years, usually I haul it into the mac store and it magically works, but I've looked through the forum and can't find anybody elses computer messing up like mine. It's still messed up. here we go:

1: I push the power button on
2: Fan and hard drive spins up fast for about 2 seconds and then stops
3: short tone plays out of speakers, (not the apple boot sound) more like an "ooooooooooo" tone for about 3 seconds, then stops
4:Light by the latch, up front, the one that usually snores, flashes violently. not steady flash but quick and crazy.
5:the screen is lit gray, no icons at all, absolutley nothing, it just sits, powered on.

I've tried holding C and various other buttons, but it makes no difference. Usually I'll boot from CD and re-install the OS, but I'm sick of doing that. sometimes it works, but usually it re-occurs three months later.
disc utility says all the discs are fine, nothing needed for repairs. SMART is fine as well.

What do i do? anyone, anyone?

Bad RAM looks to be culprit.

Take out that 3rd party stick and see if it boots.

I've heard that before, but this happened before I upgraded to the 1 gig. I think the internal ram might be f'ed. how easy it that to replace? anyone done that before? I'm pretty handy, but worried about ripping apart my laptop.
also any other ideas on what could be wrong or is it def bad ram?