HSERIN / SERIN Problem with 16f690

[mister_e]

Floating MCLR?
LVP is OFF?
Noisy PSU?
Poor contact, low battery, are some other great tests..

You could also begin your program with something like...

START:
        HSEROUT ["1,2,1,2 TESTING....",13,10]
        FOR MyVAR=0 TO 250
                HSEROUT ["MyVAR=",#MyVAR,13,10]
                NEXT
        GOTO START