LIXIL GIESTA 2 (GIESTA) MIWA QDN608+QDK668, electronic lock alarm abnormality repair

"It stopped working with the card key at the entrance from the morning."

The client is a young housewife.She was explained by phone, but she couldn't judge because she didn't know the outline.
It's a detached rental property, but is it YKK or TOSTEM?
Upon arrival and confirmation, it was a 7-year-old product "Jiesta" with an S-shaped push-pull grip handle.The design is good and there is a sense of unity.

It is a type that pushes a switch and holds the card over.

The client was able to enter the room because he also carried an emergency key, but it did not function as an electronic lock.
The location of the battery is confusing, not on the indoor side like YKK, but next to the door.I don't know where the instruction manual is.

We pursued design, but maintainability is low.As a client, it was easy once I knew the location, but it seemed difficult to find out.