Asus x442u 3v & 5v drop

[Yosua]

hi friends, I hope here someone can help me with the problem asus x442u which at 3v and 5v voltage drops, this is a measurement on the IC UP9003Q (PU8701)

pin 12 AC_BAT_SYS:19V
pin
pin 6 3VADSW_EN ; 0.34V
pin 20 5VSUS_EN: 045V

[mon2]

Re: Asus x442u 3v & 5v drop

For the rails that are low - remove all power. Meter in resistance mode (2k scale). Then check & post the resistance to ground. Then review if the resistance reading is very low then this is the cause for the voltage drop. May be linked to a shorting cap on the respective rail. If the rail is 0V, check if the regulator is being ENABLED - check if the rail has a valid INPUT to the regulator. Post your updates.

[Yosua]

Re: Asus x442u 3v & 5v drop

For the rails that are low - remove all power. Meter in resistance mode (2k scale). Then check & post the resistance to ground. Then review if the resistance reading is very low then this is the cause for the voltage drop. May be linked to a shorting cap on the respective rail. If the rail is 0V, check if the regulator is being ENABLED - check if the rail has a valid INPUT to the regulator. Post your updates.

I'm a little clueless, do I have to measure the resistance on each pin on the PWM ic, or on each coil on this mobo?

[Yosua]

Re: Asus x442u 3v & 5v drop

For the rails that are low - remove all power. Meter in resistance mode (2k scale). Then check & post the resistance to ground. Then review if the resistance reading is very low then this is the cause for the voltage drop. May be linked to a shorting cap on the respective rail. If the rail is 0V, check if the regulator is being ENABLED - check if the rail has a valid INPUT to the regulator. Post your updates.

this is the measurement on each coil on the mobo sir
PL8901(CHG_LX) :505OHM
PL8701(5VSUS): 425 OHM
PL8702(3VADSW): 338 OHM
PL8301(1.8VSUS): 335 OHM
PL8302(1.05VSUS): 48 OHM
PL8104(+VCCSA): 18 OHM
PL8102(VCCCORE): 5 OHM
PL8101(VCCGT): 4 OHM
PL9100(NVDD LX1): 14 OHM
PL9101(NVDD LX2): 14 OHM
PL8601(1.2VO): 151 OHM
PL9300(1.35VPHASE): 82 OHM


there is a change here, on pin +3vao the PWM IC becomes normal 3v, but on the enable pin 3v and 5v it becomes 0.07v

[mon2]

Re: Asus x442u 3v & 5v drop

The +3VA rail appears to pass through PU8801. Measure & post the voltage readings for each pin of PU8801.