So, I finally got around to get myself a replacement DC-DC board, and guess what? No change. The problem has to lie elsewhere, but I do not know where to look for it. Maybe microcracks somewhere on the motherboard, I don't know.

I feel that I now have the below alternatives:

1. Throw it in the parts pile

2. Get another mainboard

3. Get another powerbook with a cracked screen

What do you guys think? It's not that I really need this machine, but you know how it is. It's a nice little machine after all.