How can I be sure that my EC chip is dead?

[double_DD]

Hi all,

As the title suggests, how can I be sure that my EC chip is really dead?

I've recently gotten into this hobby of laptop repairs, and have successfully brought back to life a couple with some easy fixes, mostly shorted caps.

Now I'm working on HP Probook 455 G8, that had some "devil" run around on 3V line, burning a bunch of stuff. Luckily I have a dead 455G7 (for spare parts) so I managed to fix it (swapped burned parts) to a point that it will charge (both on barrel jack and usb-c), but it doesn't want to turn on. There is a 3V3 on a keyboard connector that does go to 0V when PWRBTN is pressed and this does go to EC chip, I've followed the path. There is also 3V_alwaysON present on EC chip. There is no shorts on any of the caps around EC.
EC in question is Nuvoton NPCX797HA1BX.

The way my current level of understanding is, if EC chip has 3V Vcc, and PWRBTN reaches to EC chip, then the EC chip must be dead. Or?

Is there something else that might be dead, thus preventing the laptop to turn on?
When any charger is connected, the LED on the PWRBTN very shortly turns ON, and then goes back to OFF. Nothing happens when the button is pressed, also there is no current change on the charger.

455G7 does appear to have the same EC chip, my last idea is to try and swap them (I know they usually need to be programmed and I don't have the programmer, but I've seen that on some HP's programming happens on board).

Any suggestions will be highly appreciated.

Thanks in advance!

[rumpumpel1]

>>>>Is there something else that might be dead, thus preventing the laptop to turn on?
yes, several hundred other parts, which may be defective.

What is the current consumption (without battery)? Is it constant? Is there any initial peek?

[double_DD]

Hi,

Thanks for the reply.

I've opened another thread, please see here.

Thanks.