Asus FX504 not charging battery

[mon2]

Re: Asus FX504 not charging battery

No, do not short the mosfets.

Remove the battery.

Apply the external power adapter that should be the original and recommended unit for this laptop.

Measure the voltages for the DCin mosfets. Post the readings for each mosfet,

Source
Gate
Drain

Also interested in the charger IC voltage readings.

For the TI BQ charger series, ACDRV should be ~25v so that the 2 x DCin mosfets enable to pass through the adapter voltage. This voltage should be on the gate pin #4 of the N-channel mosfets when the adapter is plugged in to the logic board. If the voltage on pin #4 is not this value, then some condition is not being met for the charger IC or the charger IC is defective or not soldered properly if it was replaced.

[Roll]

Re: Asus FX504 not charging battery

OK, original ASUS 150W adapter that shipped with this laptop connected, battery disconnected.
PQ21
D: 19,95 V 75 kohm to gnd
S: 0 V about 8 Mohm
G: 0 V 3,4 Mohm

PQ22
D: 0 V 200 kohm
S: 0 V
G: 0 V 5,5 Mohm

ACDET - 2,7 V
CMPIN - jumping around 0,165 V
CMPOUT - around 0,170 V
BOOT - 0,126 V
VCC - 20 V
others are 0 or almost 0. There are no shorts to GND on this IC

[mon2]

Re: Asus FX504 not charging battery

What is the voltage on the following pins of the charger IC?

ACDRV
REGN

[Roll]

Re: Asus FX504 not charging battery

They are both 0 V.

[mon2]

Re: Asus FX504 not charging battery

Remove all power. Meter in resistance mode.

Measure the resistance to ground for the REGN pin.

One meter lead to REGN, other lead to ground.

Post the reading.

Repeat for ACDRV.

If the readings are not low resistance, the charger IC is defective and must be replaced.

The REGN should be ~6v when this chip is powered by the battery or external power adapter. Confirm again that it is receiving the voltage on the VCC pin.

[Roll]

Re: Asus FX504 not charging battery

Oh my god, you are the best. I checked it - no short on those lines, so I replaced the charging IC again and now it works AND charges!
So the first IC was faulty. Good thing I ordered two of them.