@David-TP 

Thanks for the response.  Yes I have had this router a long time.  As far as I can see it is a Version 1 model and the firmware build is Firmware Version:0.1.0 0.9.1 v0070.0 Build 160613 Rel.40404n - which seems to be the only one on the TP-link site for this model.  If there is a more recent firmware for this device, please tell me where to find it.

I have not spoken to EE (my provider) as the manifestation of the problem is usually that I get an email to say my Hive device has gone off-line.   When I check the Archer device, the DSL light is usually off.  A quick reboot (power off & on again) restores the connection, so if it is a problem with the provider, it doesn't last very long, which is why I suspect the modem/router as being the issue. 

I have read that some users have experienced issues with this router being used in tandem with a TP link TL-WR710N, I have one of those being used in Client mode to feed signal to a TV and a Hard Drive recorder.  The TL-WR710N is plugged in to a standby power device controlled by the TV so when the TV is off, so is the TL-WR710N.  When the TV is powered on, the TL-WR710N will get an IP from the router (which allocates IP addresses dynamically).  However, the loss of internet connection doesn't appear to coincide with activity powering on, or off,  the TV and TL-WR710N so I doubt it is a factor.  Does that provide any clues ?

If it helps, my full setup is that I have 4 devices connected to the router (PC, Hive and a BT wifi via mains extender, plus a Netgear switch that connects my hard drive storage and a network printer (HP Laserjet pro).  The wifi extender sender has 3 receivers in various locations, two of which are wired to Sonos Speakers and the third connects to a remote PC. I have tried disconnecting various devices but still have the intermittent problem when that happens, so again, I'm not convinced the other devices are causing issues.  

Finally, this is quite an old device.  I have EE fibre plus for internet.  Can you recommend a replacement from your range that would do the same job?

Thanks. 

  @David-TP 

Hello - thank you for your reply.  Re your question the wifi extenders are the following:-

BT Mini Wi-Fi Home Hotspot 600 Multi Kit with wired AV600 Powerline and N150 Wi-Fi

Thanks for the recommendations, although I am a bit reluctant to buy a new device without  more concrete evidence that the Archer is at fault. Ironically, I've not had a drop out since our last exchange.  Assuming it does happen again, is there anything I can check on the router before re-booting it that would assist with a diagnosis?

Possibly clutching at straws but could  the following have any bearing on the issue please?

1. Is it possible that the DSL filters could be contributing to this problem?.  I have tried the EE 17070 call and tested for a silent line, which proved the line was quiet(no noisy crackling or hums).
2. Could a failing DSL cable connecting the modem / router to the DSL filter cause this sort of issue?
3. I have noted is that the outer case top, just in front of the cenral antenna (above the TP-Link logo) gets quite warm compared to the rest of the case.  Is that normal?

Thanks.

  @David-TP 

Hello,

I have now removed the Archer 1200 from my set up and re-installed the EE broadband router supplied.  That was a week ago, and so far I have had no repetition of the drop outs I was experiencing (anything from 1 to 5 days before havng to reboot the router).   I haven't changed any DSL filters or cables connecting the devices.  This rather points to the Archer as being the culprit, but it could be that I have a wrong setting somewhere.

Attached are screen shots taken from the EE router setup pages. You can't get at a lot, but here's what can be seen / changed.  The settings shown are the "as is".

I have struggled to find equivalent in the Archer for some of them - probably just my lack of knowledge on terminology.  ULA, DMZ, UPnP for example.  This is a last ditch attempt at getting the Archer working.  If that fails I'm left with buying a new one I guess?

Thanks for your help.