Chosen Solution
I have an Apple Watch Series 3 A1861 GPS & Cellular I replaced the screen by myself. The touch is working 100%, But I Needed to reset my device and after that my watch is not pairing with my iPhone. Help me!!
This is a bit of a dated reply but when I replaced a series 3 screen (see my ifixit repair guide) the display worked but I didn’t have touch and I couldn’t pair the watch. I re-opened the watch and reseated all of the ribbon cables. To my delight I was able to get touch and also pair the watch. The issue may be not having all of the ribbon cables seated properly.
Are you getting pop up message like pairing failed on iPhone screen while trying to pairing?