Dynabook Tecra A40-E - How to replace the CMOS RTC battery

[kordex35]

Hello
I have a laptop dynabook tecra a40-e
Motherboard model Dynabook Inc. 10 PCBA 7
I have to enter the date and time every time
I realize that the CMOS battery is dead, I can't locate it
RTC backup is not working
I kindly ask my esteemed colleagues for help, maybe a diagram
Thank you very much in advance

[mcplslg123]

The mb is on your table and you cant locate the cmos battery-then how do you expect us to locate it for you friend?

[rogfanther]

Please, post pics of both sides of the motherboard.

[kordex35]

The board from the battery side, no BIOS battery, no battery on the other side either, please provide a diagram, it will be easier to locate

[nosfay]

BIOS battery is certainly built in the laptop battery, you should check if it's faulty or not.

[kordex35]

Any tips on how to check without a schematic it will be difficult

[nosfay]

Just measure battery voltage with a multimeter. Or if you can boot in OS, you can check if battery is dead or not.

[kordex35]

Well, yes, but I don't know the main battery pinouts, so please send me the schematic

[nosfay]

I don't have schematic, just remove battery and measure voltage between ground and all other pins.

[kordex35]

But there is still SDA SCL control, how to distinguish it from the cmos battery

[nosfay]

If you have 0v at every pin, battery is certainly dead anyway.