Here's the solution for water damaged or accidentally dropped Samsung Galaxy S that result to SIM card error problem or the device doesn't detect or recognize any working SIM card inserted to it. This solution covers only for hardware repair if you already tried firmware calibration but the problems till exists.
On Samsung Galaxy S the SIM card slot or holder were mounted on another PCB assembly together with the microSD card holder and the speaker connection. If the flex connection of the said board become damaged it will result to speaker problem, memory card problem and the sim card problem.
The solution below shows the connection of the SIM card 6 pin connector of the Samsung Galaxy S.
The colored lines showed where each of the SIM card pins connects to the pin to the PBA connector.
Hints to fix the Samsung Galaxy S that do not detect or recognize SIM card:
1. Try to use another known good sim card.
2. Visually check the SIM card holder for possible damaged, clean it, re-solder and fix if the pins were misaligned. Replace the whole SIM card PCB board assembly if necessary.
3. Check/clean the SIM card PCB assembly pin connector.
4. Check the VSIM supply voltage. You can read around 1.8V -3V when the sim card is inserted.
5. Trace each of the VSIM, SIM_RESET, SIM_CLK, SIM_IO and GROUND pins connections down to the pin connector.