Left Joy Con not working

Have switch lite that had a run in with the heat register and melted the orginal shell. Replaced shell with new. Along the way i also had to replace the screen digitizer. I replaced all buttons a joycons as well to fit the new look. The problem is after doing all the replacements my left joy stick does not work. I tried putting the original back in and same thing. All buttons work perfectly but the left joy con does not. I just recently replaced the board and i have the same results.

Do you mean a Joy con or the small doughter Board in the switch lite?

In the lite, it can be a Problem with the long flex cable or the fpc Connector on the Main board

I have replaced the joycon the doughter board and the flex cable and have the same issue. is there a specfic way to check the fpc connector?

Normally you can See if there are broken or bend pins