For a Deco showing offline, TP-Link's disconnect article gives the drill. A satellite that flashes or stays red has lost the main Deco. Swap the problem satellite with a working one, moving each to the other's location: if the disconnection follows the unit, contact TP-Link support, and if it stays in the original spot, interference or obstacles are the cause, so adjust placement per the placement guide. If several or all satellites are red, check how they are connected. By Ethernet, unplug all cables, remove any switches between the Decos, wait a few minutes and see whether the connection improves. By wifi, move the Decos closer and reposition them. Reboot from the app: Network, the network map, the unit, the top right button, Reboot, or unplug and replug.
The checks in more detail
If the LED goes off, then solid yellow, then solid red, then white or green, the unit is rebooting itself: check it uses its original power adapter and swap adapters. Firmware: make sure all units are current. A reset through the app should remove satellites first and the main Deco last. If a Deco is listed offline in the app but has a solid light, check the modem and the app connection.
If two satellites fail together, look at what they share, such as a switch, a circuit or a wall. If only one fails, look at that unit's own cable, adapter and location. This is the same logic as swapping units, and it usually finds the cause faster than resetting anything. Keep the box and label of each unit; the model and serial number on the base are needed for warranty claims, and photographing them before mounting saves climbing a ladder later.
Differential
Likely causes of “TP-Link Deco mesh wifi mesh node or satellite is offline”, and how to tell them apart
- 1
A satellite out of range
What separates it The satellite is pulsing red because it is out of range of the main Deco
How to confirm Move the satellite closer to the main Deco, until the light stops pulsing red
- 2
A switch between units
What separates it The wired satellites show red because a switch sits between the units
How to confirm Remove the switch from between the units, at least for a test
- 3
A failing power adapter
What separates it The Deco reboots at random because its power adapter is failing
How to confirm Swap the adapter for another one, and watch whether the reboots stop
- 4
Old firmware
What separates it The units drop offline because one of them is running old firmware
How to confirm Update the firmware on all of the units, then check that they stay connected
- 5
A failing unit
What separates it The fault follows the unit when you swap two satellites because the unit is failing
How to confirm Replace the unit under warranty, since a failing unit will keep on dropping offline
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which unit is red and how it flashes
- How it connects to the main Deco
- When the unit drops offline, and how often it happens
- The firmware version of each unit in the network
Try in this order
0 of 7 completedRead the LED
ReversibleRead the light on the unit, since pulsing red means that a satellite is disconnected from the main Deco.
Reboot the unit
ReversibleReboot the unit in the app, or by unplugging it and plugging it in again.
Swap two satellites
ReversibleSwap two satellites, and see whether the fault follows the unit or stays in the same place.
Remove switches
ReversibleRemove switches from the path for wired tests, so that they are not the cause of the fault.
Move closer
ReversibleMove the units closer for wireless links, keeping them within fifty feet of each other.
Swap adapters
ReversibleSwap the adapters between units if there are random reboots, to test which adapter is bad.
Update firmware
ReversibleUpdate the firmware on all of the units, since old versions can cause them to drop offline.
Model-specific
What is true of this model and not of its siblings
- LED
- The M5, P7 and M9 Plus do not show pulsing red the way the M4 and E4 do.
- Replacement
- A single unit can be replaced and added back.
- Other models this page answers
- These steps also fit the Deco BE63 mesh, Deco XE75 mesh, Deco X55 mesh, Deco M5 mesh.
Stop boundary
When this stops being a self-service repair
- !If the fault follows a unit to a good location, contact TP-Link support
- !If all satellites are red on wired links, check the main Deco and switches
- !If a unit will not power on, replace it
Evidence ledger
Sources behind this answer
Main, satellite, client and random reboot fixes.
Every LED color and pattern by model.
Reset versus reboot and the app and button methods.
Wired backhaul rules.
The company and its products.
Exact questions
Common questions
What does solid red mean?+
Solid red means that the Deco has an issue, such as no internet connection.
How do I reboot a Deco?+
In the app, Reboot, or unplug and replug.
How do I reboot the network?+
You reboot the whole network by choosing Reboot Network in the Deco app.
Why do the lights cycle?+
The Deco is rebooting by itself.
Should I remove switches?+
Yes, remove switches for testing, so that only the Decos are between the devices.
Do I remove satellites first?+
Yes, remove the satellites first, when you are resetting all of the units in the network.
Can a bad adapter cause it?+
Yes, a bad power adapter can cause a Deco to drop offline or reboot by itself.