A TCL Q7 that says No signal on an HDMI input is either not receiving a picture from the device or not accepting the mode the device sends, and a short set of checks sorts out which. Make sure the TV is on the right input by pressing the Input or Home button and choosing the HDMI port the device is plugged into, and make sure the device is on. Reseat the cable at both ends, try a different HDMI port on the TV and a different cable, since a worn cable fails with high-bandwidth modes.
The checks in more detail
If the device is a console or PC set to 4K at 120 Hz or HDR, the TV may reject the signal over a weak cable or a port without the full bandwidth, so lower the output mode on the device and test, or use the HDMI 2.1 port on the TV with an Ultra High Speed cable. In the TV's HDMI settings, check that the full format is enabled for that port only if the cable supports it, and turn it off to test. HDMI-CEC can confuse inputs: if a device is turning the TV to a different input or the TV is switching off, disable CEC for a test in the TV's settings.
A soundbar or receiver between the device and the TV may not pass the signal, so connect the device straight to the TV. Power cycle everything: switch off the device, unplug the TV and the device for a minute, plug in the TV first, then the device. A device that does not output a signal needs checking separately, for example a streaming stick that needs its own power and not the TV's USB port. If one port fails and the others work, that port may be faulty. Update the TV software.
If no device works on any port and the TV is set to the right inputs, the TV's board needs service from TCL. If the TV worked and then stopped showing a signal after a power cut or a storm, power cycle the whole chain as described and wait a few minutes, since the TV's HDMI circuits sometimes need a full discharge. A surge can damage a single port, so test each port with the same known-good device before concluding that the whole TV is faulty. Keep the cable's rating in mind: an old cable labeled High Speed can carry 4K 60 Hz but not 4K 120 Hz.
Differential
Likely causes of “TCL Q7 QLED Google TV shows no signal on HDMI”, and how to tell them apart
- 1
The wrong input selected
What separates it No signal message
How to confirm Choose the right HDMI input
- 2
A bad cable or port
What separates it No signal on one port
How to confirm Try another cable and port
- 3
A mode the cable cannot carry
What separates it Black screen at 4K 120 Hz or HDR
How to confirm Lower the mode or use an Ultra High Speed cable
- 4
CEC or a receiver in the chain
What separates it Inputs switch or no picture
How to confirm Disable CEC and connect directly
- 5
A device without power
What separates it The device shows nothing
How to confirm Power the device separately
Before you touch a setting
Record this first — changing settings destroys the evidence
- The input and port
- The cable
- The device's output mode
- Whether CEC is on
Try in this order
0 of 6 completedSelect the right input
ReversibleAnd turn on the device.
Reseat the cable
ReversibleAt both ends.
Try another port and cable
ReversibleUltra High Speed.
Lower the output mode
ReversibleOn the device.
Disable CEC
ReversibleFor a test.
Power cycle everything
ReversibleTV first.
Model-specific
What is true of this model and not of its siblings
- HDMI 2.1 port
- Use it for 4K 120 Hz.
- CEC
- It can switch inputs.
Stop boundary
When this stops being a self-service repair
- !If no device works on any port, contact TCL for service
- !If one port fails, use another
- !Update the TV
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why does my TCL Q7 say no signal?+
The wrong input, a cable or a mode.
Can a cable cause it?+
Yes, for high modes.
Can CEC cause it?+
Yes.
When is it the TV?+
If no device works on any port.