Powerbook G4 12" power components?

I have a powerbook G4 12" that does not power on. It quit on me in late 2007 and since has just been taking up space in a closet. I originally sent it along with 3 non functioning iphones (1- 2g, 1- 3g, 1-3gs) to cash for iphones. They told me they would give me $158 on the website for all 4 items. So I sent them, now they called and took their offer to $40, then up to $80. Such a scam! So they are sending it all back. What is a G4 that does not power up worth to a refurbisher? As I remember it was working fine until it just one day would not turn on (and the newer MacBooks just came out). Is there an easy fix to making it turn on? I remember always having a problem with the G4 generations power supplys and the internal component to it, and always having to figit with it to get it to connect (this was with both G4 12" and 15" that I had). Is there a fix for this? Or is there any way to change the power components in a G4 to those like the Macbooks? Thanks for any input. Now that I was getting scammed by this company I have interest in getting the computer working again.