Basslink has located the fault in its electricity cable that has plagued users since late last year but has pushed back the date of restoration by almost a month, affecting the availability of an adjacent data cable.
The cable operator had been searching for the fault on its electricity cable connecting Tasmania to the mainland since last December when it was first identified.
Earlier this month it said it had located the likely location of the fault to about 98 kilometres from the Tasmanian coast following extensive work trying to find it.
Today the cable operator said it had pinpointed the fault location to 90km from the Tasmanian coast and had removed it from the cable on Sunday.
It said it had yet to determine the cause of the fault and was currently undertaking forensic testing.
But despite removing the fault, Basslink has pushed back the date of return to service by almost a month to mid-June. Just two weeks ago the company said the cable would be back up and running by late-May.
Basslink said it had discovered water that had penetrated the cable as a result of the fault had caused more damage than expected, meaning a third joint was now required.
The company would also need to restock its repair ship, the Ile de Ré, with cable to connect the additional replacement join, adding extra time to the repair process.
Basslink said it was making "every effort" to return the cable to service as soon as possible, but this would likely now extend into mid-June to take into account the water damage and expected poor weather.
"The jointing works are highly susceptible to weather conditions as each joint will require a continuous clear weather period to allow it to be safely completed," the cable operator advised.
The repair ship will spend the next ten days preparing for the next phase of works in Geelong, during which time Basslink will load around 100 tonnes of spare cable and add extra expertise to its repair team, it said.
“The analysis process, which saw us cut the cable 1150m from the fault, has been encouraging," Basslink CEO Malcolm Eccles said in a statement.
"This represents a difference of only 0.4 percent of Basslink’s entire cable length, which is a great result and vindicates the extent of testing and analysis undertaken."
On March 11, Basslink commenced its cut and cap operation to its data cable to allow for emergency repairs to the adjacent and faulty electricity cable.
The cut resulted in significantly degraded internet speeds for customers of the TPG-owned iiNet group after the internet service provider failed to switch enough capacity over to alternate subsea cables operated by Telstra.
iTnews later revealed that TPG had inherited insufficient redundancy plans as part of its acquisition of iiNet and Internode.