Router Disconnections - Wiring Issue?

I'm on an ADSL only plan with Snap, and my router (Asus DSL-N12U) has been dropping connection completely (not just wireless drops) very frequently at my new apartment.The router is new, and I have tried to test with a friend's router as well, same model, but same problem. Their router works fine at their place.The disconnection problem started when I moved in, but it only used to drop about once or twice a week. Now it only stays connected for a few minutes to an hour or so, and never reaches full speed anymore. I've tried factory resetting it, and uploading a settings file from the other router to my one, but it doesn't help.Snap ran some tests and told me its either the router or the wiring. Since it doesn't seem to be the router, I think its a wiring issue?Is there anyway to confirm this though? They charge a lot if it turns out it wasn't a wiring issue. Would I hear static in the phone if I found one to plug in, even though we don't have a phone connection with Snap?The apartment only has one phone jack, and the wiring is connected to each one individually, so nobody else's activity should be affecting my connection.Edit: Also, router keeps telling me the telephone cable not connected. I have tried two different ones though.Main errors from both system logs:Jul 1 02:40:19 WAN Connection: The cable for Ethernet was not plugged in.

Jul 1 02:41:08 pppd[357]: No response to 10 echo-requests

Jul 1 02:41:08 pppd[357]: Serial link appears to be disconnected.

Jul 1 02:41:08 pppd[357]: Connect time 77.8 minutes.

Jul 1 02:41:08 pppd[357]: Sent 65909847 bytes, received 2311069320 bytes.

Jul 1 02:41:08 DSL-N12U: auth-down starts

Jul 1 02:41:08 dnsmasq[316]: read /etc/hosts - 3 addresses

Jul 1 02:41:08 dnsmasq[316]: using nameserver 202.37.101.2#53

Jul 1 02:41:08 dnsmasq[316]: using nameserver 202.37.101.1#53

Jul 1 02:41:08 DSL-N12U: ip-down starts

Jul 1 02:41:08 PPPoA: Disconnected

Jul 1 02:41:14 pppd[357]: Connection terminated.

Jul 1 02:41:14 pppd[357]: Modem hangup

Jul 1 02:41:18 upnpd[338]: Failure obtaining ip address of interface ppp0

Jul 1 02:41:24 pppd[357]: Connected to 00:aa:bb:01:23:45 via interface eth2.2.1

Jul 1 02:41:24 pppd[357]: Using interface ppp0

Jul 1 02:41:24 pppd[357]: Connect: ppp0 <--> eth2.2.1

Jul 1 02:41:27 pppd[357]: PAP authentication succeeded

Jul 1 02:41:27 pppd[357]: peer from calling number 00:AA:BB:01:23:45 authorized

Jul 1 02:41:27 DSL-N12U: auth-up starts