Using a 16F877A with a New Haven serial display. Once in a while, like one time out of 30 times, when I give this board power the display goes all black. At first I was thinking something was wrong with the board or PIC until I built another one. Then I thought maybe it was a problem with the serial display. So I put some code in the PIC that turns on and off a couple outputs 50 times a second. Then I hooked up the scope to the output and powered up the board until I got the display to black out. The outputs from my PIC didn't do anything. So that is telling me its a problem with my PIC and some deal with the initial power up .

I have built a board with a normal 5v regulator and then another board with a Dc/DC converter. I am doing the converter for other reasons yet it does the same thing with either. I have the MCLR pin tied to VDD with a 4.7k resistor and diode like on the ICSP diagram found on MELABS website.

Do I need a cap on the MCLR line? Would that help? I am traveling now and thought I would put this up on the forum. I thought maybe I need to activate the power up timer. Will that fix the problem or do I need to add hardware?