Mine is doing the same thing it just keeps turning on the logo and turning back off! I called sharp they sent me too Roku then Roku send me back too sharp and they’re saying because i brought the tv 3 years ago it’s nothing they can do! I send 696 for 65 inch nothing huh?! Send us all out new TVs or something!
If you are only seeing a black screen on your TV and unable to perform a factory reset, it's possible that it's a hardware issue.
Please contact your TV's manufacturer directly to report this issue and request additional support. Each Roku TV manufacturer provides direct support and warranty services for their products running the Roku OS.
If you need a replacement remote for a Roku TV, you would need to contact your TV manufacturer. You can contact Hisense here: https://www.hisense-usa.com/support/ or at 1-888-935-8880.
So after countless hours on the phone with the run around from Sharp and Roku, then, countless hours of research, then, purchasing a power board and main board with no luck, I’ve finally figured out my ‘stuck at bootup’ issue. So, I thought I would share. I have a 58” Sharp Roku Tv that was having the same issue as all of you except my back lights were out. But when you held a flashlight to the screen you could see the boot sequence happening over and over. So after I replaced the power board and main board with no luck, I figured maybe the issue was the LED’s. So I tore the panel apart and tested the LED’s and found a bad strip. Unfortunately I broke the Display while dissembling but I still put it all back together bypassing the bad strip to see if it fixed the boot issue and it did. So it is in fact a hardware issue more then likely and not Roku’s as I thought is was. There is a fail safe that if the circuit isn’t complete or if the TCon Board has a low voltage the tv will power off, then back on to realize the low voltage again, then power off in an endless cycle. So after I had it working I hopped on FB Market place to find a TV that I could hopefully use the display off of and in the comments of a tv for sale for parts, someone commented “it’s probably the LED’s I’ve replaced hundreds in these TVs” Hope this can help someone fix these pieces of junk. Maybe Sharp and Hisense should recall these TVs that only last 18 Months. I know I’ll never buy another.