My Problem
Battery on G4 had failed, and would only hold a charge for 5-15 minutes. After using it this way for around a year (keeping it plugged in to the wall) it finally stopped powering up/charging unless i had the plug on the laptop positioned in the perfect position. This required a delicate balancing act of placing the plug on a book etc. and leaving the laptop hanging off in order for the charging light on the plug to go green. Eventually it stopped charging/workin
My Fix
The repair was very straightforward and easy. I left my laptop partially apart until the part arrived. After receiving the part, the repair took only 10-12 minutes. The computer came back to life after 3 or 4 months of sitting dead.
My Advice
Attached pictures are of the old DC Inboard for reference. Hopefully they help in your diagnosis. Notice the very small dark circle above-left of the TEST/OK sticker.
Written on January 4, 2012