Error codes for IT 310T-B

Two of my devices displaying “err” after a few seconds delay.
First has Audio code every 3 seconds.
Second has continues Audio code.
Is there a list of this codes available.
If there is a chance to repair no problem.
I just fix one of the devices by changing the relay inside.

This may be caused by damaged probe or faulty time chip.
Please check if the probe and probe cable are intact? If the probe is wiped clean with a rag and dried, will it still trigger ERR?