The broken printer frayed Ross Armstrong's last nerve.

The Oakland, Calif., resident had to make photo copies of the death certificate of his late husband, Jay Stern. But it was Stern who had always handled home tech repairs, and Armstrong broke down at the small but horribly timed irritation.

"Having the printer break was the straw that broke the camel's back. I thought, 'What else now?' " said Armstrong, 60.

Nearly two hours on the phone with Hewlett-Packard and $90 later, a new printer was on its way. But Armstrong left it in the box, he said, without the first clue about how to set it up. He googled "Geek Squad," the tech support and repair service owned by Best Buy. The results Google gave him included another name: Geekatoo.

Once a tech expert arrived, Armstrong thought, "Boy, am I glad I didn't do this."

If that sounds familiar, it's because Geek Squad has been offering it since 1994. But start-ups have declared that business too slow and expensive.

Geekatoo is among the largest, with 7,000 independent contractors across the country; it has raised $2.1 million from investors since 2013. Eden, which launched in May, has raised $1.3 million from investors and employs about 35 people. And Enjoy, another start-up that emerged in May, has about 140 employees and has raised $30 million.

The U.S. tech support industry makes about $30 billion in annual revenue, according to research by Parks Associates, a consulting firm. With the Internet of Things — devices such as thermostats, locks and hot water heaters that are connected online to gather and share data — the need for home service is expected to grow.

"When I look at the market opportunity and all the wireless systems that people want to get installed at home, it's a great time" for these companies, said Rebecca Lynn, a general partner with Canvas Venture Fund, which has backed Eden.