[jen729w]

My neighbour's internet was terrible last year. He replaced a bunch of stuff, and went as far as switching ISPs to my recommended provider. Nothing worked.

Finally a savvy helpdesk person had him move his ADSL router. I believe he moved it off a cheap power board and plugged it directly in to the wall.

All problems immediately solved.

[e28eta]

If it’s being moved inside the house, it could also have been a different phone jack that made the difference, or a different cable connecting to the jack.

[jen729w]

It wasn't that. It was the power board.

[PaulHoule]

ADSL is particular sensitive to electronic noise. I'm afraid to set up my HF ham radio again.