switch it off at the socket for 5 mins, switch it on, if it's the same try a factory reset (pin in the hole for up to 15s while power is switched on).
If it's still the same it has failed. Consider whether to complain to retailer.
Flashing lights are random behaviour of dying electronics, doesn't look good.
MaxDSL - goes as fast as it can and doesn't read the line checker first.