Phones won't work without power adapter

[randagc]

Hi folks,

having an issue with some Mitel 5320 and 5330 phones. Not all of our phones but maybe 6 out of about 100 power on via POE but don't display anything on the screen nor do they allow me to boot into config.

However if i connect them up to a power adapter and leave them disconnected from the network and power them on, they come up fine. If i then connect them to the network, the phones then work without any issue.

If the Lan is connected before powering the phone on though, i get the same issue as if i was powering up from POE i.e. all the lights on the phone go on, but nothing appears on the screen and it just stays like that. No dial tone or anything.

Any help would be appreciated here, as i really don't want to replace these 6 phones, I'd rather know what is causing the issue and resolve it.

thanks for your help in advance.

[acejavelin]

My gut reaction is a switch issue, something configured on the ports or a slight POE incompatibility or overload of the switch... but since it does the same thing with a POE injector with the network connected but not when it is disconnected, it still leads to believe it is a network issue.

I would start with defaulting the phone, wipe Main and reload it, and test again. Possibly try a different POE switch as well.

[dilkie]

late comment but have you tried other cables... I know there is a difference between the older and newer sets wrt POE and how to signal/request power. The old sets used some unused pairs in the cable, the new follow a different spec... or something like that... I've run into this before.