Partial answer, right click anywhere on a blank area f laptop screen, go to properties an left click, you should see options for adding a external screen, add it. You can also locate the tiny screen emblem on upper keys on the laptop and press this key while plugging in the HDMI cord this sometimes will do the trick. Also get the source menu up on TV and choose HDMI 1 good luck.
Sounds like The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
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