No Power, IC replaced and charging port is good

My switch no longer powers on or charges at all. I have sent my switch to get repaired by 2 different third party repair shops now. 1 checked the usb c connector and battery and said they were both good but could not provide a service for the IC repair. I sent it to another shop to get the IC replaced because I was sure that was the issue but they just told me that they replaced the IC chips and it still does not power on and can only think that it is a GPU or CPU issue.. Thankfully neither place charged me for the work done since the issue was not fixed. Am I SOL or is there anything else I can do to try and get this guy up and running again? I would really rather not buy a new switch since they seem to be impossible to find/scalpers suck. I am desperate here!