Hardware Swapped Housing and now Joy Con won't connect

[PoppaDre]

Before swapping out joy con housing the controller connected fine. After I finished I reconnected the controller in handheld mode and it was working however the switch didn't register it as connected to the console itself. After a reset I lost functionality all together. The controller will not connect to my other switch either. It snapps when I slide it in the switch but it has a white animation instead of the green. When i press sync it lights up but is not detected.

 

[SENSENuii]

Take the joy-con back apart and make sure that everything is connected

 

[PoppaDre]

Take the joy-con back apart and make sure that everything is connected

Anything specific I should be looking for? I took it apart again and everything looks connected

 

[SENSENuii]

Anything specific I should be looking for? I took it apart again and everything looks connected

Yes, make 100% sure that all the ribbon cable connectors are latched down.

 

[bowser]

Because the ribbon cables are so small they may look like they're all the way in even though they're not.

 

[PoppaDre]

I am thinking the ribbon cable on the rail is damaged. I see some discoloration so maybe it is loosing connection

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Because the ribbon cables are so small they may look like they're all the way in even though they're not.

Is there anyway to test them or determine which one is causing the problem?