Sonoma County's nearly 35,000 food-stamp recipients couldn't use their debit-style cards for most of Saturday after a computer snafu knocked out the purchasing system in 17 states.

Frustrated cardholders heard rumors that the problems were linked to the federal government's partial shutdown. But vendor Xerox Corp. blamed the problem on a routine test of its backup systems that resulted in a system failure.

Xerox announced late Saturday that access had been restored for users in the 17 states affected by the outage. Along with California, the outage affected Alabama, Georgia, Iowa, Illinois, Louisiana, Massachusetts, Maryland, Michigan, Mississippi, New Jersey, Ohio, Oklahoma, Pennsylvania, Texas and Virginia.

The outage affected those enrolled in the Supplemental Nutrition Assistance Program, or SNAP, assistance commonly referred to as food stamps. In California, it's called CalFresh.

The problem began Saturday morning. Soon cardholders or their family members were reporting that stores around Santa Rosa and Rohnert Park were unable to process purchases with the cards, which use a system known as electronic benefits transfer, or EBT.

Teejay Lowe, CEO of G&G Supermarkets in Santa Rosa and Petaluma, acknowledged the frustration for both grocers and residents who depend on the system to put food on the table.

"We're both at a loss of trying to feed people when these things don't work," he said.

Rayma Zwinge, a retired nurse who lives in Rohnert Park, has grandchildren who benefit from the program. She said frustration over the outage was exacerbated because of repeated talk at the stores her family visited that the food stamp program had been affected by the government's partial shutdown.

That made it sound like food-stamp recipients might have to wait a long time to use their cards again.

"It's so frustrating," Zwinge said.

U.S. Department of Agriculture spokeswoman Courtney Rowe underscored that the outage was not related to the government shutdown.

The Associated Press reported similar experiences around the country. Shoppers in Biddeford, Maine, left carts of groceries behind at a packed Market Basket grocery store because they couldn't get their benefits, said shopper Barbara Colman, of Saco, Maine. The manager put up a sign saying the EBT system was not in use. Colman, who receives the benefits, called an 800 telephone line for the program and it said the system was down due to maintenance, she said.

"That's a problem. There are a lot of families who are not going to be able to feed children because the system is being maintenanced," Colman said. She planned to reach out to local officials. "You don't want children going hungry tonight because of stupidity," she said.

Ohio's cash and food assistance card payment systems went down at 11 a.m., said Benjamin Johnson, a spokesman for the Ohio Department of Job and Family Services. Johnson said Xerox asked retailers to revert to a manual system, meaning customers can spend up to $50 until the system was restored.

Illinois residents began reporting problems with their cards — known as LINK in that state — on Saturday morning, said Januari Smith, spokeswoman for the Illinois Department of Human Services.

In Clarksdale, Miss., one of the poorest parts of one of the poorest states in the nation, cashier Eliza Shook said dozens of customers at Corner Grocery had to put back groceries when the cards failed Saturday because they couldn't afford to pay for the food. After several hours, she put a sign on the front door to tell people about the problem.