An anonymous reader writes: NBN Co has been forced to replace 10,000 faulty broadband devices in homes across the Blue Mountains west of Sydney after residents reported the technology was frequently struck by lightning and in one instance led to blue sparks flying out of a modem in a family’s home. About 20,000 of the more than 32,000 homes in the Blue Mountains and Emu Plains have been connected to the national broadband network via fibre-to-the-curb (FttC) technology, which was set up under the Coalition government’s multi-technology mixed model. That means fibre runs all the way to the edge of the property and connects to the home via the existing copper wire lead-ins from the curb. Electrical storms in the Blue Mountains have wreaked havoc on the boxes that link the fibre to the copper. When lightning strikes the distribution boxes outside the house, sparks are sent flying up the copper lines, in turn frying the modems in people’s homes. Guardian Australia understands the company has replaced 10,000 — or half — of devices inside the home that the company has identified as being prone to be affected by lightning. A spokesman for NBN Co confirmed that the company had found issues with the devices in areas of hard ground like sandstone. Sandstone is more resistant to electrical conduction than other soft earths. He said the devices fail in a safe way but the company nevertheless is issuing replacement devices people can install themselves. “We are now deploying a strengthened [device] that is much less likely to fail in these conditions.Read more of this story at Slashdot.