I have faroe_dis_x32_mb_mv laptop motherboard. Problem is battery not charging. Have replaced charging ic bq24780s and tried new battery. Both old and new battery shows 0v backup.
-
-
Re: Battery not charging
hey!
1) review the datasheet from TI for this charger IC.
2) the logic board will be a 99% clone of the reference schematic.
3) then study the battery mosfet. With NO power - confirm the resistance of this mosfet (see the many posts from myself and others) - you are checking for a low resistance across the mosfet pins = defective mosfet and needs to be replaced.
4) Do check the HIGH SIDE / LOW SIDE mosfets that are feeding the battery charge pins.
5) Next, confirm with the adapter of the voltage that is at the battery pin. What do you see ?
6) Do note, as we have seen it here before, the CURRENT sense resistor and circuit on this charger IC. The case took 3 weeks to solve but there was a broken PCB trace from the current sense resistor TO the charger IC. This caused the charger IC to believe too much current being drawn and forcing the rail to sink to 0 volts => shut down the charging leg of the IC !!
Check without power, the resistance from each side of the current resistor TO the respective pin on the charger IC. The readings should be ~0 ohms.
Post relative readings of questions.
Comment