Original battery got lost so I got a new battery on Amazon. With the battery installed, the battery light would always blink orange fast. Computer would not turn on. With battery not installed you can power up and run the computer fine on the power supply.
I figured it was a bad battery so I sent it back. I then bought an authentic Sony battery. That one does the exact same thing. Searching on this board I find all kinds of different answers. No two answers seem the same. Without having another known-good computer, or known-good battery, how do I figure out what the problem is?