good luck, i've done a search myself and a lot of others models are available but not this specific one in the EU. I'd rather try to source a whole damaged Powerbook G4 for cheap, same model as yours and pray to have this board working.
If they are damaged they are damaged right there.
so common failure point ? Even if you find it it will be probably be refurbished or new old stock and prone to fail the same no ?
They still sell new spare parts, I have one here for a 2004 if someone wants.