The Greek Prime Minister, Antonis Samaras, faces crisis talks with coalition allies over his decision to shut down the national broadcaster.
The conservative leader's junior partners in government were furious about the sudden decision last week.
Mr Samaras accused ERT of corruption and waste, as the country struggles to pay its huge debts.
Greece's top appeals court is also meeting to rule on whether or not the closure was legal.
ERT's screens have gone from black to showing colour bars and the name of the new-look broadcaster proposed by the government, Nerit, now features in channel searches.
If the court comes out against the closure of ERT, the prime minister will face pressure to row back, reports the BBC's Mark Lowen from the capital, Athens.
Mr Samaras says a new leaner, cheaper broadcaster will be established within weeks and he has proposed hiring a small team to produce news programmes in the interim.
But this idea has been rejected by his coalition partners, who demand that the ERT signal be restored.
If no deal is reached, the government could fall and Greece could slide into fresh elections, plunging the Eurozone back into chaos, our correspondent says.
However this is unlikely, given that the two smaller coalition parties have poor poll ratings and so are reluctant to face another electoral test, he adds.