A friend has had her Sky Decoder box start sparking, issuing smoke and with an acrid smell. (11 Aug 2020)
Luckily she was home when it happened and turned the power off
The Sky technician is getting a replacement.
Just found a NZ Herald report from 2016 on the same subject...
https://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=11707633