Sek error with p02 and p21 on Heidelberg pm 52

[Sunilvaryani]

Dear sir
Can anyone inform how to clear this sek error on pm 52
Our electrician has checked the switches but still he says he needs to
Check one by one on unit 2
I'm attached some photos
Can anyone help
We have this error not going on the
Machine since year and half
Regards

 

[Sunilvaryani]

The electrician told me that these are
Errors in unit 2

 

[boooch]

SEK error occurs in the stop button or cover switch.

 

[Sunilvaryani]

SEK error occurs in the stop button or cover switch.

Ok sir, he's checking which switch is giving the problem