Quote Originally Posted by rsocor01 View Post
I also see that you don't have a diode in MCRL protecting Vdd from Vpp. From the PIC datasheet, the maximum absolute value that Vdd can take is around 4.5 V. If the programming voltage, Vpp, is greater than 4.5V you might have damaged the PIC by no using a diode.

I don't see anything else that might be causing problems.

Robert
Thanks again, Robert. The ISCP is not providing Vdd for the board. Vdd comes from a 2.5V regulator. I verified with a 'scope that Vdd is not changing during programming. I can see the programming data coming in at 5V, but PORTB is 5.5V tolerant.

Best Regards,
Paul