1. Are you not able to program that particular board? If yes, please check the voltage on the VCCD pin when the device is powered. The voltage on the VCCD pin should be 1.8 volts. If not then the device might got damaged.
2. If you are not able to program any board then please check whether Miniprog 3 is working or not. For that please check what all LEDs are glowing on Miniprog 3 and check the status according to the Miniprog 3 user guide Appendix A.1 obtained from the link below:
3. Please go through PSoC programming troubleshooting guide:
Please reply after trying above 3 points.