Energy Department Director Kevin Garlick said Monday that a small percentage of lines suffered a decrease in signal strength during recent cold spells, disrupting service.

Repairs, he estimated, could top $100,000 to a system that already is funneling millions from Provo's budget.

Garlick said staffers have narrowed the problem to the 96-fiber-count lines within the network, but they don't yet know how many of those lines are malfunctioning.

"When it warms back up, it doesn't seem to be a problem," Garlick said. "That's still not acceptable to us. We're just now trying to get a handle on the extent of the problem and what the ultimate solution will be."

The iProvo network is a citywide, city-owned fiber-optic system that provides phone, television and Internet services.

Garlick said he expects to learn more details about the bad cables today, but he estimated fewer than 5 percent of the lines pose problems.

The replacement tab - and who would end up paying it - remains in the air, Garlick said. The city replaced a piece of faulty cable last year at a cost of roughly $20,000.

Mayor Lewis Billings, who has championed the network since its announced undertaking, said he didn't know enough about the glitch and deferred any comment to Garlick.

The controversial network has drained the city's budget because revenues have lagged behind operating costs and debt payments. The City Council already has approved about $3 million in loans from other city funds to cover bond payments.

Council Chairman George Stewart said Monday the council has been told iProvo probably would need several million more in loans to pay the debt.

Officials first projected the system would break even at 10,000 subscribers - Provo now has roughly 9,500 - but they now say they will need between 13,000 and 15,000 to get out of the red.

"[This] is just another challenge iProvo is facing at this time among the many challenges that it faces," Stewart said. "Had I been on the council at the time, I would not have voted for it. But, that said, we have got to pay our bond. We've got to keep it operating."

For now, the focus of the iProvo management team is to get to the bottom of the faulty fiber-optic lines. Staffers will huddle in the coming weeks with the manufacturer of the fiber-optic cables and the engineering company that installed them. City officials are unsure if the cables were bad to begin with or if the problem stems from how they were installed.

"It doesn't appear to be extensive," Garlick said, "but, nevertheless, we're conducting a survey of all the fiber."

toddh@sltrib.com