There are several things that can stop a skr 1.3 form turning up as a drive.
1) corrupted firmware. Use another method to mount the sd card on your computer (like a usb to sd card reader) and upload a known good firmware.bin to it.
Put this in your controller and power it on. Cross your fingers.
2) you enabled sdcard access to the onboard sd card. In which case you need a working lcd to release the card for the computer to access it. Reset back to default firmware.bin as per step 1)
3) "its dead Jim" hold the appropriate viking burial rites and send it out to sea in a burning boat.