Lenovo Idepad s410p changed nuvoton five times. pls Help.

[araxnido]

I tell you, several months ago I have a ls431p laptop without schematic or boardview only photos. Originally it came with a problem from KBC (nuvoton NPCE985PA0DX) since they broke the charger input and surely 20v entered through the PID line. I replaced it with a new one ordered from aliexpress, at first it turned on and showed video for a moment then I turned it off and it failed again and it did not want to turn on anymore. I have already changed it with this 5 times but the same problem continues, although on the 3rd or 4th time it turned on again but without video.
Another is that after not giving video on some occasions I thought it could have been bios that I have also tried several firmware and the original with clean ME and nothing. For now it has the original bios.
The 3v and 5v are ldo and also the signal EN1 and EN2 arrives in the 3ALW and 5ALW system, for which the 3VALW and 5VALW are permanent. On some occasion when it turns on I was able to measure the 1.3v ddr and the 0.6vtt in addition to dram_rst # (pin30) with 1.3v.
Right now I don't know what else to do, it doesn't want to turn on or give video, it's totally off.
Any idea could lead me to the glorious ignition!
Excuse my english translated by google

[mcplslg123]

Re: Lenovo Idepad s410p changed nuvoton five times. pls Help.

Grab any schematic with NPCE985 as KBC and check basic requirements of KBC like 3VA_EC/LID_SW#/EC_RST/RSMRST#/AD_ID\AC_IN etc etc.

IF you have 3V/5V on coil present, then your PSL logic is working. Try replacing the output caps on 3V/5V coils with tantalum caps.