Asus DSL-N66U fibre woes

[#1]

I bought an ASUS DSL-N66U (combined modem and router) last week to replace both the BT Openreach VDSL modem and Technicolour router. I have Plus.net fibre broadband with static IP.  Unfortunately, I can't get it to connect. 
The DSL light on the router never stays on so it seems it's failing just connecting to the exchange.  If I use the Quick Internet Setup tool, it asks me to double check the DSL cable is even connected and after 3 failures, it asks me to input the Annex type.  I've tried all manner of settings in the 'DSL Settings' and 'WAN Settings' screens but still don't even get as far as the DSL light staying on.
Has anyone managed to get the same device working with their fibre package and able to share their settings with me?  Plus.net tech support have been of very little help.
Please note that I've tried 2 brand new models of the ASUS without success, so I've ruled out a faulty device.  The Openreach\Technicolour combo work fine so I've also ruled out problems with the line/faceplate.

[#2]

Which firmware version are you using? The correct settings should be here - http://community.plus.net/forum/index.php/topic,120429.msg1079764.html#msg1079764

[#3]

Hi, I don't have a DSL-N66U but do have the DSL-AC68U which is connected directly to my line and works great.
There shouldn't be any issue getting the N66U up and running - can you have a quick look through your DSL / WAN settings as a starting point, and check they match up with the last screen grab in: http://community.plus.net/forum/index.php/topic,134288.0.html ? Also please be sure your device has the latest firmware installed.
If that doesn't sort it, could you post a screengrab of your current settings minus username/password?
What's shown in the router's system log? It should hopefully be recording some details around what it's doing while trying to connect.

[#4]

Hi and thanks for responding.
Things I've tried:
2 different brand new versions of the same router
Upgraded to firmware 1.0.7.7
Different DSL cables
Removed the BT faceplate and plugged a microfilter directly into the test socket
Changing the VDSL stability adjustment
Changing from PPPoE to Static IP and entering my static IP address
Gain Adjustment: stable
VDSL profile: 30a and 17a
Annex: A & B
I've attached screenshots of my WAN and DSL settings, as well as the log file with the settings shown in the screenshots.
Could there be some differences between various users local exchanges that might explain it?  It looks to me like Asus routers just aren't suitable for use with Plus.net fibre.  It just doesn't even get as far as the DSL light staying solid.

[#5]

Can you comfirm your using the dsl-n66u with an rj11 to the master socket and not connecting the OR modem ?
if so you have set it up to connect via pppoe and using the wan port which won't work

[#6]

I'd personally reset the n66u and go thru the quick internet setup via 192.168.1.1

[#7]

Quote from: taras

Can you comfirm your using the dsl-n66u with an rj11 to the master socket and not connecting the OR modem ? if so you have set it up to connect via pppoe and using the wan port which won't work

Yeah, the RJ11 is connected directly to the master socket (see attached pic).
The Quick Internet Setup fails after 3 attempts (asking me to make sure the DSL cable is connected) then takes me to another screen asking me whether my ISP uses Annex A or Annex B.  Both of those options fail.

[#8]

under wan and the basic config, where u have selected pppoe .. what other options are in that drop down box ?

[#9]

Automatic IP
Static IP
PPPoE
I do actually have a static IP address with my account and have tried entering that, together with
IPv4 Default Gateway: 195.166.128.186
Subnet Mask: 255.255.255.0
Primary DNS: 212.159.6.9
Secondary DNS: 212.159.6.10

[#10]

You'll probably need to leave that set to PPPoE - Plusnet DHCP will automatically assign the right static IP on connect.
Out of interest, what happens if you enter 1492 for the MTU rather than leaving it set to 0 for the default?
The DSL settings you posted look OK to me - as long as VDSL2 modulation & Annex_B are available I'd have expected the router to connect. My router's connected with the "30a " vdsl profile though rather than 17a, which it looks like is selected in one of your screenshots.

[#11]

Hi Tim
I've tried MTU 1492 with no success and no obviously useful log messages.
I think I've just about exhausted all options. Since I've had the same results with 2 different units, I can only imagine there are compatibility issues which vary by exchange. Unfortunately, plus.net official support has been on a par with Asus support.

[#12]

in basic config change your ip version to just ipv4.

[#13]

Tried that as well.  Same result.

[#14]

Can you post what's in your router log?
Leave the WAN IP Setting to automatic or it will cause issues.

[#15]

You mention ruling out a faulty router in your OP,  however  looking at this Kitz' page, it could still be in question:
Combined VDSL2 Modem Routers
ASUS DSL-N66U
[Mixed reviews. A lot of reports of DSL instability]
also see the Discussion