UPDATE 10am: THE power supply failure that caused widespread television outages in the Northern Rivers was part of planned work by Essential Energy, a spokesman has said.

Essential Energy community relations manager Mike Hely said customers in the Dunoon and Mt Nardi areas, including users of the Mt Nardi digital TV broadcaster tower, were notified in writing of the planned works.

Mr Hely said Essential Energy would be working on a high voltage power line from 8am to 3.30pm today that would likely caused continued power disruptions to customers in the area.

ORIGINAL: TELEVISION stations in the Northern Rivers including ABC, Ten, Seven, Nine and SBS have been down this morning due to a major transmission failure at the Mt Nardi digital TV broadcast site.

The tower is 30km north of Lismore in the Nightcap National Park and services the Richmond Tweed area.

NBN news technicians said the transmission failure was due to power supply problems.

ABC and Ten are the only stations that appear to still be out of service.

Seven, Nine and SBS were out for just under an hour this morning.