IP Phone changes to dial state by itself

[Marcos Eusebio]

For no apparent reasons, many of the phones that we managed are having some weird issues and we can't figure out what is going on. The phone just randomly changes its state to dial screen without human intervention, this occurs without any patron of time or date; but is more frequently in phones with high work charge like receptionist, assistants or security booths. This issue happens normally to the 8811 model (maybe because is the most common used). We've opened at least 3 TAC cases to try to resolve the problem, but nobody has found the root cause of this issue, we had to change the phone to the users to solve the problem. Here I share the most common information that the TAC engineers asked us:

CUCM Version: 11.5.1.15900-18

Firmware Version: sip88xx.12-6-1-0001-668

I've attached the PRT files generated from the phone after issue happens and a video of the failure.

[Jaime Valencia]

I would look at the device being controlled via CTI, any other remote control apps that are on the market, or as you mention that those devices are heavily used, it might be that the the clicker is dirty/faulty from the heavy use or environmental conditions and that's causing the issue.

[Marcos Eusebio · Accepted solution]

Hi Jaime, you're right.

We changed the clicker (also knew as "hook switch") with one of another IP phone in our damaged stock (with another issue) and the failure was solve. But was very difficult to do that, it takes at least 1 hour to disarm both phones and reassemble them again.

[afasja]

I had the same issue.

Just reset the phone and it starts to work normally for a while and the issue re-appeared.

Finaly i change the phone.

Just for testing., i reconfigured the old ( the phone with issue )  as a new extension and noticed the same issue, All other telephones are working normal. It seems its the problem with the the telephone.

[Marcos Eusebio]

Hi Afasja,
try to take the phone apart, clean the hook switch and put it back together. With that we have managed to correct the problem in our company. Surely the electromechanical sensor is very sensitive to dust and/or humidity.