Re: need a reaplcement power supply for Premier + - not available on Roku Accessories
Good 'ol Roku and their %$#@& product naming conventions.
There have been TWO models called Premiere+, model 4630 released 10/2016, and model 3921 released 9/2018. (Note letters following the model number denote distribution channels and don't matter for this issue.)
The more recent 3921 just uses a standard USB power adapter and standard detached micro USB cord such as you would have for many cell phones or other devices. You may purchase the Roku PW10, the first one listed on this page, from Roku. Or any high quality adapter with a 5v output of at least 1.0 amp could be used and connected with a standard USB-A to USB-micro cable.
But since you mention the pa-1120-42ru power supply you probably have the older 4630. As the 4630 has been out of production for a while information is getting hard to come by.
Image from Simon's post here: https://forums.roku.com/viewtopic.php?t=112063#p584813The same power supply seems to have been used in the sister Premiere 4620 model. The power supply for this is a 12v, 1 amp output, and has a permanently attached cord terminating in a round connector to match the DC power-in port on the 4630. In Roku's inscrutable naming way, it seems that this was sold by Roku as the PW09, but this is not available on the current Roku accessory page. Web searches for pa-1120-42ru and Roku 4630 power supply turn up 3rd party versions on Amazon and eBay.
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