The problem he was having is that the USB On-The-Go cables that he tried were never the right size or orientation. So he scavenged them for parts and built his own flat cable for a custom fit.

SMS USB 2.0 OTG Transceiver is LS/FS/HS compliant with USB 2.0 specification and includes VBUS comparators, Switched Pullup & Pulldown resistors, data Line Pulsing Blocks Required by On-The-Go ...