samsung np550 charging problem

[trmrtts]

hi all

i have samsung np550: ac adapter with not working but with battery working.charging ic bq735
vcc :19v
acdet:3.1v
acok:0v
regn:6v

i changed charging ic,I/O controller and mosfets

whats my problem?

boardview:
schematic:

[mon2]

Can you post the above in the schematic side of the forum? The above links are raising virus flags.

Is this your board?

[trmrtts]

Yes this board Mine

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of the ACP and then the ACN pins. If the resistance is too low, this charger IC will turn OFF the DCin mosfets and halt the power path that powers the board and stops the battery charging.

After the above, place one meter probe on the ACP pin (direct on the charger IC), the other meter pin on the ACN pin (direct on the charger IC). Use the lowest meter scale for this measurement. Need to know the full current sense resistance path.

[trmrtts]

acp:6 mohm
acn:5mohm

place one meter probe on the ACP pin (direct on the charger IC), the other meter pin on the ACN pin (direct on the charger IC)

: 2.4 ohm

[SMDFlea]

If the schematic is already posted at badcaps post a LINK to it,and if not then post it in the schematic requests section ,then post a link to it https://www.badcaps.net/forum/troubl...f-this-section

[mon2]

Carefully measure the voltage to ground of each pin of each mosfet at Q3 and Q4. One of these at least is probably defective.

With no power, meter in resistance mode, measure the resistance across the mosfet pins:

source & drain
source & gate
gate & drain

post each measurement.