我用的pic24hj64gp202单片机，pic单片机下载电缆用的pickit3,电路板3.3v供电，连接PGED1，PGEC1进行配置，但下载的时候出错如下：
PICkit 3 detected
Connecting to PICkit 3...
Firmware Suite Version...... 01.28.18
Firmware type......................dsPIC33F/24F/24H
PICkit 3 Connected.
Target Detected
Device ID Revision = 00003003
Programming...
Programming failed