Zyxel NR5103E v2 // Admin password recovery, help request

TheGeorge

Dear colleagues,

I would like to ask for your help with my funny, but not so funny situation with my Zyxel NR5103E v2 Router.

Yesterday when I came back home I found it reset to factory defaults and I found it the hard way, when my phone connected to a "strange" network, which was the default one. I don't want to mention that of course, nobody from my home touched the Router... wink-wink :))

The thing is that the default Wifi password was saved both to my laptop and phone, but the default web password for the admin account was overwritten in the browser, because the 192.168.1.1 default IP is a common one.

Unfortunately its labels are scraped and I don't have the box for it anymore, as I recycled it, so I am now stuck, with my hands tied, because I cannot connect to it anymore to change both the subnet, as most of the home devices have static IPs and configure the old SSID.

I tried reaching Zyxel, through the support portal, but the device was bought from the ISP, so they cannot help me by opening any ticket :(

I even teared it apart and connected to the serial console, but unfortunately, there's nothing interesting in the output, like the SN or admin password, besides the MAC Addresses that I already had.

I was thinking on connecting it to SP Flash Tool to at least do a full back-up and try to reflash it, but it's not being detected through the USB Type-A to Type-A cable, or I'm missing some points in putting it to boot mode, like you can do for the Android phones.

So, I'm here asking you for any help or direction on trying to recover the admin password, or at least its serial number so that I can ask our colleagues on other threads for a helping hand in having the credentials generated.

In case it helps you, I managed to extract this info from the webpage by using the Developer Tools in the browser and looking for the response data:

ModelName "NR5103EV2"
SoftwareVersion "V1.00(ACIQ.1)b1_E0"

Thank you in advance for your help! :)