How to find connections on board? - DIY Keyboard from Old Laptop
The CY8C24794 has USB D+ on pin 20 and D- on pin 21. Tracks from these pins appear to go to the connector on the lower right. Here we also see a thick trace with a pad marked '5V0' which I am guessing is USB +5V. Ground is probably connected to the grid pattern on the PCB, so should be easy to meter out.