No one will dive into the mainboard's circuitry with ohm meter, oscilloscope, schematics to find and fix the board. Today's repair shop would change out the mainboard or boards that do said charging and see if that fixed it.
What you can do is try the latest BIOS for the board since some boards have power management that is controlled by the BIOS.
My HP Omnibook Pavilion ZT1175 seems to kill its battery after about 1 month with a new battery. I've replaced the battery three times, and the battery company won't replace it again. The unit worked fine on the initial battery for more than a year and has worked fine with each new battery, charging and discharging normally, for about one month. Then, while on battery operation, the computer suddenly shuts down, and, from thenceforward, it will not work without the charger/power supply and it indicates that the battery is no good, i.e., the orange light indicates normal charging for a few hours after the battery is installed, but then turns red - indicating a bad battery. This current behavior is repeatable without variation.
The battery wizard (Control Panel|power options|battery optimizer) says it's not a supported battery, but it does provide status information indicating that the current is 0 ma and the voltage is ~11.4V. I checked the connector, and assuming the pin numbers start from the right looking at the connector from its side of the battery, pin 1 (the lone pin on the right) appears to be ground and pin 5 (the fourth to the left of the notch) appears to be +11.4V. Pins 2,3,4 and 6 have <.05V to gnd, and pin 7 (on the left) is about 0.18V to gnd. I assume that one pin (presumably pin 5) is the voltage sensing terminal and that one or more of the others should also have B+ voltage from which one could draw current - but they don't seem to.
Can anyone make sense of this - or, better, tell me how to get a schematic and pinout of the HP Omnibook charging circuit? I've been unsuccessful finding this information via Google or the local computer shop.
Any help will be appreciated!
Aloha from Kona