i have these la - f401p motherboard that i am working on. the problem is that it does not charge the battery up it only shows its charging but does not go up. attached is the picture of how it looks. can anyone help me.
Announcement
Collapse
No announcement yet.
la f401p not charging battery
Collapse
X
-
1) Confirm that the power adapter @ 90W matches the actual power adapter's markings. Confirm this adapter is suitable to run this logic board.
2) It is possible that the battery may be old or defective. If possible, test with another known good battery or test this battery inside of another working logic board.
3) Remove all power. Meter in lowest resistance mode. Short your meter probes and note the resistance of the shorted probes.
Locate the charger IC @ PU901. With no power to the board / no battery connected; measure the resistance between pins 1 & 2 on this charger IC.
We are confirming the full current resistance path for the battery leg of the circuit. Post the measurements.
-
These are good measurements. The total path of the battery charge resistors = 1 ohm + current sense resistor (milli-ohms) + 1 ohm = ~2 ohms.
Configure your meter into DC volts mode -> connect the battery and also the power adapter.
Carefully, measure the voltage to ground of the following signals:
PBAT_CHARGER_SMBDAT
PBAT_CHARGER_SMBCLK
We are checking if either of the above lines is shunted to ground from a defective TVS ESD diode.
Comment
-
Originally posted by mon2 View PostThese are good measurements. The total path of the battery charge resistors = 1 ohm + current sense resistor (milli-ohms) + 1 ohm = ~2 ohms.
Configure your meter into DC volts mode -> connect the battery and also the power adapter.
Carefully, measure the voltage to ground of the following signals:
PBAT_CHARGER_SMBDAT
PBAT_CHARGER_SMBCLK
We are checking if either of the above lines is shunted to ground from a defective TVS ESD diode.
Comment
-
Remove all power -> meter in lowest resistance mode. Measure the resistance from the battery connector PBATT1 pins 1-2-3 to the mosfet pins on PQ906. This is to confirm that the EMI filter beads @ PL1 and PL2 are not open circuit.
With the power adapter and battery connected, meter in DC volts mode (20v or higher scale if manual type of meter) - carefully measure the voltage to ground on each leg of mosfet PQ906.
Post each measurement.
Comment
Comment