Switch only charges in any dock

Hi there

My switch sometimes displays on the TV, but once I start up a game and start playing at, it will stop outputting signal and my TV say no signal.

My friends switch works fine in my dock, I tried everything. Unplugging the dog using a different plug in, using different HDMI ports and chords different official AC adapter, nothing.

I saw a video from a YouTuber called my mate Vince and he was trying to repair a switch with the same issue as me he replace the USB c port and it did not work for him. Switch only charges in dock.

When I saw his video I was actually going to go and take it into repair shop in town but knowing that it didn't work for him I don't want to waste money for nothing.

I couldn't find any other peoplewith the same issue as me besides one person but he took it into Nintendo but I can't because of modding reasons.

Help???