Have a G3 pismo, works great, but when I plug in the power cord, the light won't come on to indicate its charging. It is charging, and the battery is good, its just that the light won't come on. Could it be something with the backup battery?

Question

I have a G3 bronze keyboard that works, with a good battery, but when the power supply is plugged in, the charging light on the back of the laptop
will not come on. It is charging however, and have two different apple power adapters and both will charge the main battery, it's just that the light won't come on.
Did a reset of the pmu, but no changes. The date stays current, but wondering if the backup battery could be getting weak and affecting it , or is something else going on?

Answer 1

The power connector in the G3 PowerBook is a weak link.  Removed, it looks like this:
[image from http://microdocusa.com/specials.html ]
The connector probably hasn't failed, but the solder joints where "legs" on  the connector  attached to the logic/power board are under a lot of stress after 10 years of use. Little bumps and tugs on the power cord eventually degrade the connection. You can check for looseness easily---see if the connector feels loose when you GENTLY wiggle it with a fingertip. It should have zero play if it's still firmly attached. You can also plug in the power adaptor and see if slight movements if the plug make the light turn on. Pretty diagnostic of a loose connector.
The date stays current,
Make sure you are doing this check correctly. If you have an always-on internet connection, the date/time are fed froma  network time server and will always read properly unless you test with the internet connect turned off or disconnected.