The mystery of why an entire village lost its broadband every morning at 7am was solved when engineers discovered an old television was to blame.
An unnamed householder in Aberhosan, Powys, was unaware the old set would emit a signal which would interfere with the entire village's broadband.
After 18 months engineers began an investigation after a cable replacement programme failed to fix the issue.
The embarrassed householder promised not to use the television again.
The village now has a stable broadband signal.
Openreach engineers were baffled by the continuous problem and it wasn't until they used a monitoring device that they found the fault.
The householder would switch their TV set on at 7am every morning - and electrical interference emitted by their second-hand television was affecting the broadband signal.
The owner, who does not want to be identified, was "mortified" to find out their old TV was causing the problem, according to Openreach.
"They immediately agreed to switch it off and not use it again," said engineer Michael Jones.
Engineers walked around the village with a monitor called a spectrum analyser to try to find any "electrical noise" to help pinpoint the problem.
"At 7am, like clockwork, it happened," said Mr Jones.
"Our device picked up a large burst of electrical interference in the village.
"It turned out that at 7am every morning the occupant would switch on their old TV which would, in turn, knock out broadband for the entire village."
The TV was found to be emitting a single high-level impulse noise (SHINE), which causes electrical interference in other devices.
Mr Jones said the problem has not returned since the fault was identified.
What else can cause broadband problems?
Suzanne Rutherford, Openreach chief engineer's lead for Wales, said anything with electric components - from outdoor lights to microwaves - can potentially have an impact on broadband connections.
"We'd just advise the public to make sure that their electric appliances are properly certified and meet current British standards," she said.
"And if you have a fault, report it to your service provider in the first instance so that we can investigate."