That's right.

The ADSL light is an indicator of the path between your modem/router and your ISP.
If it's flickering, some data is making it, other data is lost. If it's off, no data can be exchanged.
That's in contrast to the connection between PC and modem/router; you can have an ADSL signal but still be unable to use the internet because of your local area connection.

Be aware that while your problem is definitely a physical obstruction on the line, the other points from my previous post are causes of physical obstructions, so you'll want to try those before taking measures to get a technician to work on your line. That can result in hefty charges that you could avoid.

Having said that though, I think you might need a technician on your line based on the evidence so far. If that is the case, your telco should fork out for it.

P.S. One thing I forgot to mention before is that most routers don't need to dial up to broadband. Usually they're configured to remain online at all times.