Unfortunately I believe wether the PCH or CPU is dead. Coils are not shorted to ground when I measure resistance but I can't get a stable voltage when all coils are soldered. AC light blink twice then orange (battery light) blink once.

​I thought that a dead CPU or PCH would have at least a coil shorted to ground.

Looking with a thermal camera I Can see the PCH dual MOSFET starting briefly (26°C, around 1.2v) then both CPU cores MOSFET turn on and off very quickly. All this sequence take less than 2 seconds and keep repeating. Any chance this could Come from a faulty...

Thank you but I can't expect the laptop to turn on or do anything when voltages are unstable when the board is on the test bench. I think I solved this issue as I previously replaced 1 shorted Mosfet on the CPU and at the time I think I messed up the solder. Something was wrong on this mosfet, plugging the adapter the IC would check if all tensions are good and find out something is wrong with this Mosfet then turn power off from the first AC Mosfet. I resoldered the Mosfet again properly, adding solder to padds and soldering flux. Now I have stable voltage. Leds are turning on when I plug the...

So finally I decided to resolder the down converter PU8702 and now the board is getting close to work ! I have voltage on coils. Problem is that the power is turning on and off like every second. It's just like it's trying to turn on all components but something wrong is detected and the power supply is turned off, then trying again and again. I can see the cpu heating at 30°C. Any idea on what to check ? Thank you !

Thank you mon2, actually I noticed component RT8249CGQW on page 99, which seem to create +3VAO, +5VSUSO, +3VADSWO but I cannot find this component anywhere else in the document or in the board view.

I replaced PU8702 as the former one was blown. I controlled the new one for a short between VIN and BOOT but didn't find any. Do you know any other tests to be made to ensure this kind of dual mosfet is working properly ? I found some additionnal tests on Youtube but they require the mosfet to be desoldered form the board. I was curious about the EN Pin of this Mosfet but it's connected...

Thanks for your help ! I measured 18.94 at CLR, 0v at the output of 3V regulator and 5V regulator (DOWN CONVERTER ATK1658BGQUF). I do have 18.94V at every entry point of dual Mosfets on the board. I do not see any 3V LDO in schematics. On schematics, VCC pin of IT8225 is fed with +3VS

Hi there,

I recently bought a dead Asus zenbook UX434FLA (i7 10th gen, integrated graphics, 16Gb ram). The first Power MOSFET close to DC connector was shorted so I replaced it. I now have 19v present everywhere on the board but all coils at 0v.

Resistance to ground on all coils :

1.2v (PL8601) : 262
+VCCGT (PL8103) : 6.5
+VCCCORE (PL8102) : 5.2
+VCCCORE (PL8101) : 5.2
+VCCSA (PL8104) : 36
+1.05VSUS (PL8301): 49
+5VSUS (PL8703) : 3.4K
+1.8VSUS (PL8303) : 2K
+3VA_DSW (PL8704) : 2.7K
+P_CHG_LX30 (PL8901)...

Cheers from France,

Born in the eighties the first unit I put my hands on was a venerable Pentium II I used for playing games. I studied business but as far as I remember, I always enjoyed to disassemble things to see how they work (which might be related to the death of the Pentium II mentionned earlier...). Recently I discovered the tremendous world of Arduinos/Raspberry and built my own plant watering station with wireless soil moisture sensors. I found this forum while searching hints about an issue on an Asus Laptop and I have to admit I was impressed by the level of skill i...