What can I do if the ADSL LED indicator is not on constantly on my MERCUSYS ADSL modem router?

Cause/Symptom:

The ADSL LED indicator is off or keeps flashing, which means the ADSL modem isn’t establishing proper connection with the internet line.

Please refer to the followings to troubleshoot:

1. Verify you bought the correct device

 For our Mercusys ADSL modem routers can only work with ADSL internet service. Please make sure that you bought the correct TP-Link device according to your internet plan from internet service provider.

2. The telephone cables or the splitter

There are two phone cables involved here: one from the modem to the splitter; one from the splitter to the phone port in the wall. It can be either one of them.

Please take out the splitter and connect the modem to the wall line directly or replace the above two phone cables.

3. The modem itself

Try to reset the modem first by pressing the reset hole for 7-10 seconds until all lights flash once while the modem is powered on.

4. ISP’s line issue

If above three suggestions cannot let your modem work normally, contacting your Internet Service Provider is very necessary. You may ask them to check whether the internet server of your site is running smoothly or not, to check whether the ADSL line of your site is providing signal or not, or to check whether there has some maintenance for their ADSL service around your house.

Or you can test whether your old modem is working fine with your ADSL internet line or not if you still have your old modem. If your old modem cannot work either, it would be your ISP’s line issue.