Greater Anglia and Network Rail admit they're no closer to solving the problems which have dogged rural train services across the east for more than a week.
Engineers have been manually operating barriers and using a system of flags to warn train drivers.
- Watch Rob Setchell's full report below.
It's led to dozens of trains being cancelled or delayed. Both companies say they're working round the clock to find out what the problem is.
The delays and cancelations affect rural routes serving the following stations:
- Great Yarmouth