asus tuf fx506ii DA0BKXMB8D0 REV D

[String2016]

I need help on this please, I have here asus tuf FX506II DA0BKSMB8D0 REV laptop.The problem with this is no power, 20v is presents n Dc in mosfet and current sense resistor,but I noticed BQ24780S ic is warm here is the measurement of that ic.

ACDET=2.7V
ACOK=3.2V
VCC=FROM 19.7V FLUCTUATE TO 19.6V
ACDRV=26.3V
REGN=6V
HIDRV=FROM 8.4 DROP TO 6.4 THEN GOES TO 7.1 AND GOES TO 8.4 AGAIN
PHASE=SAME VOLTAGE FLUCTUATE ON HIDRV
LODRV=0.0074 FLUCTUATE TO 0.0064V
ACP=0.0024V
ACN=0.0024V

Anyone can help this please

[String2016]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

I found PC193 connected to SRP and SRN reads short in diode mode could it be this the problem?

[mon2]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

SRP and SRN will be bridged by a very low resistance resistor = current sense resistor. This will cause the meter to believe these pins are shorted. They are not shorted.

The voltage readings for the charger IC look ok and the warm temp may also be ok.

Review the 2 x DCin mosfets driven by the ACDRV pin. There will be a 4k resistor between ACDRV and the gate pins on the DCin mosfets of interest.

Start with checking the main power rail -> remove all power -> check the resistance to ground of the main power rail. What is the resistance ? If it is low, there is a short on the main rail.

Next, review the condition of these same DCin mosfets.

Check the resistance across the mosfet pins.

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. Often, the 2nd DCin mosfet starts to leak and causes the issues.

[String2016]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

the first dc in mosfet measures S=5.2MEGAOHMS D=62K G=0L
the second dc mosfet measures S=5.1MEGAOHMS D=24.3K G=0L

BLACK PROBE TO GROUND

and below
firs dc in mosfet probe to black to source and red to drain= 0.600 megaohms
and black to source and red to gate=0l
and black to gate and red to drain=6.59megaohms

second dc in mosfet probe to black to source and red to drain= 9.19 megaohms
and black to source and red to gate=0l
and black to gate and red to drain=6.6megaohms

[String2016]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

I noticed that the 2 4k resistor connected to ACDRV pr205 and pr 206 measures only 2.3k

[String2016]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

voltages of the two dcin mosfet are good both source have 20v and drain have 20v and gate both have 26v, current sense resistor measure 24.6k resistance.also noticed there is no 3v and 5v on coils and there is no standby voltage on bios chip

[mcplslg123]

Re: asus tuf fx506ii DA0BKXMB8D0 REV D

There is nothing wrong in the charging circuit. Move On to check basic requirements of SIO. 3V/5V may appear only after turning on. make sure keyboard is not faulty by shorting the power on pins manually.