Tstart errors third party ip phone

[DatennetzEWS]

Hi, Some of the ip phone do not working on POE port Cisco 2960X-24PS-L, Power Controller reports power Tstart error detected. Plug in this phone to another vendor switch, then it is working fine. We have updatet the switch to the latest release. Also tried several thing described in other communities:

Longer cable (>50ft)
Switch(config-if)# power inline port 2x-mode

Any help will be greatly appreciated, thanks

[saif musa]

Hi, 

Chick below, it will help.

https://quickview.cloudapps.cisco.com/quickview/bug/CSCsw18530

Regards

[DatennetzEWS]

Thanks for your reply. But how I have mentioned, we tried to put the port already in 2x-mode, unfortunately nothing changed.

[saif musa]

Hi,

Sorry for being late answering you.

The document shows that this issue is a known issue to cisco and they consider it as a bug, anyway. They says that 2x-mode can solve this problem and it can be used for platforms that support this feature, for non supporting platforms they would rather use longer cable which can give the same result in maintaining inrush current inside the cable. 

I recommend you use longer cable beside putting the port to 2x-mode and see whats happens. also, you didn't mention if you are using 3rd party ip phones rather cisco ip phones.

Regards

[DatennetzEWS]

Thanks for your persistence to support me. We don't use cisco ip phone. We also tried already a longer cable, approximately 40 meters. The cable diagnostics shows us short circuit. So will try tomorrow again a very long cable in combination of 2x-mode on the port. If this will not help, we have to use another vendor switch until cisco will fix this bug? BR