Zyxel NR5103E wrong firmware (POLAND)

Hi,

I have a Zyxel NR5103E router (serial number: S230Z12028890) and I accidentally flashed the wrong firmware onto it — V4.19(ABYC.5)C0, which is made for the NR5103, not the NR5103E.

The reason I attempted to flash new firmware was that the NAT restrictions were limiting my ethernet connection to around 312 Mbps, while the router itself provides 600 Mbps+ over WiFi. I was trying to resolve this performance issue.

As a result of the incorrect flash, WiFi is no longer working on the device. LAN and cellular connections still work, but WiFi is completely broken.

I bought the device second hand so I am unable to get support from the original network provider. I attempted to contact Three UK directly but their community forum requires registration with a Three UK phone number, which I do not have. I have also searched online extensively for the correct NR5103E firmware but cannot find it available for download anywhere.

Could you please help me restore the correct firmware? The device label shows the Three UK logo, so I believe the correct firmware would be the Three UK ACBJ variant.

My details:

• Model: Zyxel NR5103E
• Serial number: S230Z12028890
• Current (wrong) firmware: V4.19(ABYC.3)C0

Thank you!

(For safety reason, Zyxel agent has removed some device's info)