I once got sudden problems on turning on my PB 5,9, and although I don't remember details that well anymore, I think it also didn't start with or without battery anymore (these computers should run without battery just fine too).

Resetting PMU (Power Management Unit) did help in my case and the issue never came back after that, it's been running fine for years now after the incident with the same battery.

So I'd advice to google how to reset the PMU on your particular model and try that, it was an easy operation.


[ Edited by jPV 28.02.2019 - 16:33 ]