Yealink T48s will not factory reset

[simplyict]

I have a Yealink T48s touchscreen unit that will not factory reset.
After at least 10 attempts to hold down the OK button for 10 secs to get the factory reset option and press ok, after restarting , the unit still has the provisioned data from the previous owner.
The admin password is not admin, and the unit still has a programmed DSS key to dial out on it.
The webpage won't let me in as the password is not admin either.

Any suggestions to fix this issue.
It simply won't factory reset.

 

[ClsVip]

This may be due to the IP phones being provisioned via Stun to another 3cx Instance, Does the phone come up with the option to enter username and password, once it is factory reset?

 

[JohnS_3CX]

You have some kind of autoprovisioning most likely

1. DHCP Option 66 - Disable option 66 on your network, or find the extension under which this MAC address is assigned and delete it from the PBX

2. 3rd party RPS entries - you need to contact Yealink for this one

 

[simplyict]

Hello
ok so yes it does come up with name and pwd on the phone rebooting. but the standard admin admin does not work. and the phone still has a number up on the top left corner indicating an extension.
funny thing when it resets, it reboots and then when it comes back, it has no number and no service.
then it reboots again and then it comes up with service and the number in top left.
yes it am assuming it is auto provisioning. but a wipe should delete that.

no I have no DHCP option 66 running
This phone was never attached to my 3CX PBX so can't just delete it.
I have other T48S units and they all reset fine. just not this unit.

 

[JohnS_3CX]

Ok that pretty much settles it, you need to contact Yealink and request that the MAC is removed from their Auto-provisioning service.

 

[simplyict]

damn i wonder how long that will take. oh well. ill give it a try. many thanks

 

[MikkelAnd]

If it's autoprovisioning from Yealink, maybe you could try to prevent it from accessing the the provisioning service?
A DHCP reservation with a dummy gatewat or blocking the traffic in your firewall.

That way you should be able to provision it locally, which I *think* would override SNOM provisioning.

/mikkel

 

[simplyict]

So i just turned off my internet connection to prevent it reaching out. Everything else was still running.
using a Unifi USG pro 4 gateway.
Still no luck resetting the damn phone. even though it ssays no service and no numbers on the display, there is still no way to login to the phone.