BQ40Z80: Can't communicate to BQ40Z80

Part Number: BQ40Z80

Hi,

I 'm doing a circuit about BQ40z80 and communicate to BQstudio by EV2400.

It could have been normal communication to BQstudio, but suddenly it didn't work.

Bqstudio can detect the EV2400, but can not detect the guage bq40Z80 either add a 24V voltage to Pack+ or connect a 24V battery cells with a reminder of "No acknowledge from device".

The phenomenon is that :

When  add a 24V voltage to Pack+ and no battery, the voltage of cell 7p is 3.7V

When add a battery of 24V vaoltage to the circuit and PACK+ is no_load , the  voltage of Pack+ is 13V.

Could you please help to tell me what would this phenomenon?

Thank you !

Best Regards,

Iris Weng