New LPC2210 on PCBA which cannot access by JTAG

[lpcware]

Content originally posted in LPCWare by JW_SG on Mon Aug 31 02:44:40 MST 2015
I have made some PCBAs and assemble the new LPC2210 MCUs on boards. I can't access by JTAG and can only be programmed by ISP mode for the first time programming. Why?