To recover the affected TV, you should reset it to factory default settings. You may need to contact the manufacturer if they don’t provide the steps to perform the reset as part of the devices documentation.
With 2017 predicted to break the record set in 2016 for ransomware, occurrences such as this will likely become more common.
Unfortunately, TV manufacturers are unlikely to pre-harden vulnerable devices before shipping them due to compatibility concerns and increased costs (during manufacturing and later support costs). To increase use of their after sales service they are again unlikely to publish the key sequences or button presses to perform a factory reset.
The ransomware encountered by this software developer was “just” a screen locker. It didn’t also try to encrypt any connected USB drives. Separately, a Symantec security researcher published a helpful list of mitigations to protect against ransomware targeting Smart TVs.
Continuing the trend of protecting Internet of Things (IoT) devices (defined), I hope that you find the above mitigations useful. Please also refer to this previous blog post for more general advice on preventing ransomware infections on your everyday computing devices (non IoT devices).