PIC16F87-based project only works when ICD is plugged in

[dhorvath]

I have a problem on a recently upgraded project where everything works fine as long as my ICD-U40 is plugged in, but as soon as it is removed the device stops working.

I have RB3,6,7 all dedicated to the ICSP port, and MCLR tied high through a 47K resistor, GND and VCC appear fine. Using the internal oscillator at 8 MHZ.

These seems like it must be something simple, but I'm stumped... what do I need to check for?

[Ttelmah]

Have you got the pull down resistor on B3?.
If you have the chip programmed for LVP (implied by using B3), this line _must_ be pulled down, for normal operation.
Section 15.18 of the data sheet, note 4.

Best Wishes

[PCM programmer]

See this thread:
http://www.ccsinfo.com/forum/viewtopic.php?t=28356