Check the label under the battery for the exact model number (e.g., TJ-850, TJ-726) and search online for firmware tailored to that version.

Do not insert or remove the SIM card while the router is powered on—this can damage the SIM reader.

A: Most models support 8–15 devices. Trying to connect more may cause disconnections.

Leave a comment below with your specific model number (look for "TL-TJ..." or something similar on the sticker), and I’ll try to help you debug it.

), the core configuration is managed through a web user interface accessible via a browser Shenzhen Tianjian Telecom Technology Co., Ltd. Initial Hardware Setup Insert SIM Card