@HannZ 

Hi, I would like to follow up on your case by email, and please have a check of your email box.

At the same time, could you please help me confirm more details:

1.When you said “the 1st deco will not work if I turn off the 2.4GHz”, did you mean Deco would no longer broadcast 5GHz and you could not detect any wireless signal at all?

2.If you try to enable the guest network for 5ghz, would you be able to use the 5Ghz network?

3.If you put the 2nd Deco next to the main Deco, would it be able to wirelessly connect to the main Deco? if yes, could you please help me check the backhaul on the 2nd Deco, like via 2.4ghz or 2.4ghz/5ghz?

Thank you very much.

HannZ wrote

@TP-Link 

1. Can't detect any WiFi and show red blinking light.

--Is it tested when the first Deco worked as the satellite unit or the main unit?

2. For now I have swap the second deco as my main. 

--Did the new main Deco(the second Deco) start broadcasting 5ghz now, or also running 2.4ghz only?
3. Since I have swap the second deco as main, the 1st deco as the slave,  the slave is showing 2.4Ghz only. 

this specific deco (1st deco) giving a lot of different issues. Line keep dropping, running 2.4 GHz, failed to  add on after reset.( only connect via Lan cable) etc. 

@HannZ 

Could you please help me confirm the above details?

@HannZ 

Hi, Thanks for the update.

I have forwarded your case to the senior engineers and please have a check of your email box.

@dc1191 

Hi, the previous case is more likely to be caused by the broken 5Ghz wireless module on one of the satellite Deco units so a replacement has been recommended.

I see that your device is Deco M4 and could you please provide more details about your current issue?

Thank you very much.