This solution below can be used to troubleshoot and repair a damaged Nokia 5130 that has a Memory card problem issues such as Memory card not detected or the device unable to detect the memory microSD card even it is being already inserted.
Ensure to update the device flash firmware first before you may proceed to used this solution.
There is a detector switch on MicroSD slot holder that triggers the device to activate the MMC circuit, check it if it is still working. You can read a voltage on that spots when the microSD is not inserted and then it dropped to 0 volts when the microSD card is inserted.
Check and ensure also the MicroSD card holderfree from dust, dirt, molds and oxidation build up, clean it if necessary.
Check the supply voltage of the MMC controller chip