Post updated on Dec. 8 to reflect new details on the cause of problem.

The Microsoft Surface tablets used by NFL players and coaches on the sidelines were rendered unusable during Monday’s bout between Dallas and Washington, but the NFL says the problem wasn’t with the tablets themselves.

An NFL spokesperson tells GeekWire the problem stemmed from “the power to the server that manages the still shots.” The situation forced the teams to go old school and fire up their paper printers to analyze plays.

Here’s what Dallas Cowboys head coach Jason Garrett said after the game:

“We didn’t have tablets, and we didn’t have pictures. We went through an issue typically if the headsets are off for one side, then they immediately go off for the other side, and they aren’t allowed to use them, but the NFL was working their way through a ruling with tablets and pictures, and it took us a little while to make sure things were balanced on both sides.” “It’s a challenge. It’s a challenge because you get so used to seeing those pictures and verifying your thoughts. So what you have to do is communicate really, really well as to what is going on. The guys upstairs have the best vantage point of fronts, coverages and the different looks that we are seeing so they have to do a good job at taking and writing that stuff down because you don’t have the opportunity to go back and see the pictures or see the stuff you would typically see on the tablets. So I think our guys did a good job communicating and working through that challenge because it is different.”

Thanks to Microsoft’s $400 million, five-year contract it inked with the NFL in 2013, players and coaches have had access to the custom-built Surface tablets for the past two seasons with an application that lets them be more efficient in how they review past plays. The idea is to replace the traditional printed paper black-and-white images of plays to analyze previous possessions, and instead use the waterproof tablets that allow for annotations on each photo with the Surface Pen.

The NFL introduced players and coaches to the Surface Pro 2 tablet last year, and this season Microsoft is upgrading the devices to a ruggedized, weatherproof version of its Surface Pro 3 tablet, which offers a bigger and thinner screen, lighter weight, clearer images, and a pen that can be used in four different colors.

Microsoft ran into a separate marketing issue during the first game of this season, when Al Michaels mistakenly called the Surface an “iPad” on national television. This seems to be a recurring problem for Microsoft — last season, commentators referred to the Surface as an “iPad-like tool.” It happened on more than one occasion last season, with Trent Dilfer calling the tablet an iPad during a Monday Night game, too.