Lenovo Legion 5 missing EC_ON_5V signal (5v_AWL)

[questore]

Dear all.
I have a Lenovo Legion 5 that come to me as faulty.
The problem was that Adapter_ID pin was shorted by some liquid... killing the EC (there was a hole in the EC) (therefore 3.3v was shorted)
I have removed shorted EC it and tested that if i short EC_SBM_CK1 to ground, then the BQ24780SRUYR power IC lets 20v pass the first and second mosfet.
Nothing else seems shorted when checking 3V,5V, 1.1V, battery or 1.0v coils, so I have ordered the new EC chip.

I have ordered a preprogrammed Chip for NM-C921 and soldered it on. (No pins shorted after checking all)
Plugged in the AC adapter but only 3V_AWL is coming on.
3.3v is present on power button and goes to 0v when pressed. (also checked on EC_Pin to be sure the info is getting there)
I have found that EC_ON_5V signal is never comes out from the EC.
I have tried 3 different ME_Clean bios but no luck. EC does not sending 5V_ON so 5V_AWL never comes on

Can anyone help what could be the problem? Is the new EC faulty or wrong BIOS can cause this?
Thanks for all the help!

[questore]

SOLUTION:
The EC pin number sahara boards in bookpc's (3vALW_R) had a lose soldering.
After resoldering it, the laptop turns on and everything work fine.
Thanks for the help.

[mon2]

https://www.badcaps.net/forum/troubl...vo-y530-legion

[questore]

I have tryed 2 different BIOS from this forum to reprogram BIOS with Clean ME.
Both of them are not working and acting like the original symptom.

If a wrong BIOS is present then shouldn't the 5V_ON signal come on anyway with 3.3v?

[mcplslg123]

Check resistance to GND on 5VALW and 5V LDO.

If the resistance reading is ok, very likely bad sio/bad soldering or bad EC firmware.

[questore]

+ 5V LDO is Present after charger plugged in. (5.02 Volts)
+ 5VALW missing when plugged in (resistance 0 ohms when plugged in) and normal resistance when charger is not plugged in (Mohms)
+ EC_ON_5v is 99 Millivolts both case (when charger is plugged in or not)

If I inject 5V on 5VALW then the 3v/5v voltage generator IC is getting hotter a bit (drawing 0.230 Amps and 39C degree)

MY IDEA:
I want to inject 3.3v on the EC_ON_5V line and see if the 3v/5v IC is turning on +5VALW. and SYSPWROK signal. If not then the 3v/5v IC is faulty, if it turns on then EC firmware is wrong. (Or BOTH 😂)
( in my region no one programs EC as I know, so maybe i have to invest 500 Dollars to a programmer )

[questore]

Unfortunatelly it seems that the EC programming is bad or something seriously wrong with board

1. if I short the charging IC CLOCK signal to ground, the battery starts to charge, otherwise not.
2. if I touch the EC_ON_5V pin with multimeter when charger is connected, then suddenly 2.6V is apearing on the pin, and 5VALW is turning on stabile.
3. if I touch the EC_ON_5V pin after 5VALW is turned on with a multimeter, then the EC_ON_5V voltage is disappearing along with 5VALW goes to 0v and I cannot turn it on again anyway until charger is disconnected again

Am I right to think that EC has wrong firmware?

[questore]

SOLUTION:
The EC pin number sahara boards in bookpc's (3vALW_R) had a lose soldering.
After resoldering it, the laptop turns on and everything work fine.
Thanks for the help.

[questore]

I see some automatism changed my text.
Pin 127 was lose.