Error E21 - need a bit of help

[Grubi]

Hello, I guess you laugh on me... Trying to repair old japanese rice cooker ECJ-AD18E (I think inductive one), with error on display E21. Seems nice and clean, except natural aging - no sign of damage. I replaced also 3V battery, old one was dead, so display and clock works well Since it is inductive - coil give me 0.6 Ohms and I can't see any failed temp fuses. I can't find any manual or comment on such error. I know - it is very old, but have santimental value...

Thanks in advance if someone can give some direction! If I am totally on a wrong place, delete my post.

[m k]

With electronics.
Right place, no doubt.

Take few pictures.