Hundreds of Sky Glass television and Sky streaming service customers have reported issues with their devices.
Users first reported technical glitches seemingly preventing some Sky Glass TVs from working properly or even turning on Thursday evening.
Reports to platform outage monitor Downdetector were in the hundreds shortly before 21:00 BST on Thursday.
But many customers were still flagging issues with their devices on Friday morning.
"We are sorry that some Sky Glass and Stream customers are currently experiencing issues when trying to switch on their devices," a Sky Spokesperson said.
It said customers should try to manually restart their TVs and devices, by following a guide on its website.
One user on social media complained to the company's help account on X (formerly Twitter) that their Sky Glass TV had not been working for nearly 11 hours.
"We pay a lot of money each month for the use of your services and understand at times faults happen, but 11 hours so far with no end in sight, it's not good," they wrote.
Sky Glass is a smart TV that works over broadband and allows owners to stream content directly to their device - without the need for an aerial or satellite dish.
Users affected by issues with the device have speculated that a faulty update from Sky could be the cause of "bricked" TVs.
One user posted a video on X showing their television not turning on, with its red standby light slowly flashing.
Customers also shared frustrations and tried to find workarounds for the issues on Sky's community forum.
One user said they were "regretting buying" their Sky Glass after the technical issues caused them to miss out on TV, including the first half of a Champion's League football match.
Users have also been reporting similar issues impacting the Sky Stream "puck" that provides access to film and TV shows from apps including Netflix and Disney+.
Sky did not respond to questions about what had caused the issue, or when it expected problems to be resolved.