3GS SIM card reader issues

i have 4 iPhone 3gs’s with this exact issue. i tried to put the board into another housing to sell, and it no longer will read sim cards correctly. when i insert a sim card, It says No SIM in the top left, but sometimes will have carrier settings and phone number show up in settings, but those take over a minute to show up.

if i power it off and back on with the sim card installed, it will say Searching… and continue to say that even if i remove the sim card.

They all used to read sim cards perfectly before i removed the boards, but no longer will in the new housing or when i put them back into the original housings.

There is no way i damaged all 4 of them when removing from the housings/putting into the new ones. doesn’t seem to be an issue with the 2 gold bars at the bottom of the reader or the 6 gold sim card contacts.

Also, the one i’ve been messing with will now say No service, then says no sim card installed about 15 seconds after i take it out, but won’t recognize the sim being re inserted until powered off again, then it just repeats.

if you have any ideas of what the issue possibly could be, or if you need more info or photos, please let me know. thank you