I do have experience in electronics and troubleshooting, but nowhere near as complex circuits as this “new-fangled” mainboard.

Thank you very much for the tip, because it's enough to at least start tracing the wires.

Am I right in assuming that the button cell pulls up the RTCRST#/SRTCRST# pin, reduced in voltage by a diode? If so, one of the solder jumpers should also have the button cell voltage or the reduced button cell voltage applied.



€dit: Correction: If the voltage of the button cell were applied to the solder jumper...

Ahaaa! Thanks for explaining the process. So the problem is just to find the pins wich are probably​ pulled high or have a missing GND bridge.

As I dont have a shematics you maybe can hint me how to find these pins or the traces that are conected to? The Board has some solderjumpers but unfortnatly HP did only wrote the reference but not a name to them.


I know what is a SPI ROM At the ES Laptop its in a socket so I just need to find the right adapter/tool to read it....

As the title say I need the shematics of the HP EB 820 G3 to find the signals RTCRST# and SRTCRST#.

A small guide or just a picture would also be sufficient.

Please read Here to get more infos:
[url]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/3332624-elitebook-820-g3-engineering-example-cmos-settings-lost-despite-new-cell[/url]

Thanks,
Roberthttps://As the title say I need the ....<br /> <br />

Ah! So I need to find the pins on the southbridge and check if they are connected to the CMOS cell? This is the right hint, because I suspected the Nuvoton chip to be faulty.

Am I interpreting correctly that the CMOS setting is stored in the southbridge?​

Edit:[URL]https://edc.intel.com/content/www/jp/ja/design/ipla/software-development-platforms/client/platforms/alder-lake-mobile-p/intel-600-series-chipset-family-on-package-platform-controller-hub-pch-datash/system-power-supplies-planes-and-signals/[/URL]


Edit2: [url]https://www.mouser.com/...

I read about these pins/conncetions but i did not found a Datasheet of the nuvoton chip.

Do you have this?...

Hi there, im Robert, 38 and from west Germany.

Regular i'm an mechancal engineer but i have a passion for electronics too.

I made my registration because i got hands on a HP Elitebook 820 G3 engineering sample and have trouble with the ES BIOS.