omron plc cpu20 memory err

Hi everybody.
On omron plc cpu20 ihave constant memory err
After bettery drain and plc got out of power i removed all errors with pro15 but i cant find program in ram .all lines in pro15 are with ???? .This mean program lost?Is there any way to restore it or recover?

thank you in advance

It sounds like you have a C20K or C20 series Omron controller. The full part number should be printed on the top or side of the PLC.

Yes, your program is lost.
The only way to restore it is to reload from a paper copy or backup if you have it.

You will have to replace the battery, or your program will not be saved in the ram memory.

These controllers also have the ability of an EPROM. This is located under a hatch on the top of the CPU. If the socket is not empty, there is a chance the program might be on it.

https://accautomation.ca/omron-c20k-c28k-c40k-c60k-troubleshooting/

https://accautomation.ca/purchase-find-parts/omron-c20k-c28k-c40k-c60k/

Regards,

Dear Garry
Thank you for your fast reply.
Rom socket is empty.
No way to retrieve program now?
regards