I've tested this as a tuner for a digital pc monitor with hdmi input, and "no signal"! When attached using AV cables it worked on a roku smart TV, fine. However, THAT device never needs a separate tuner, so it's superfluous. The Roku TV also says 'no signal' when attached to this GPX tuner using an HDMI cable. We tried a couple different HDMI cables which work well when used to connect the monitor above to a computer. Monitors work- check, Cables good - check. HDMI output on the device seems to be the culprit here. Their tech support phones in to DPIINC which was great, short wait times, understanding my issue, etc. But, when they contacted GPX customer support after vetting my call. They got nothing but an answering machine...
I bought this product when the tuner in my tv stopped working properly. It's working great so far and I love the recording feature, plus it's priced right!