Thread: PIC16F877 not executing?
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Unread 19-06-2008, 08:55
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Re: PIC16F877 not executing?
I usually use a 10K resistor to pull MCLR up. You should probe that pin with a voltmeter to see where it is. You might have a solder bridge or other short somewhere that's messing you up.

The next thing to check is that your crystal or oscillator if you're not using the internal oscillator is functioning as it should. I've seen PICs get into a strange states and do weird things when their crystal/oscillator isn't working correctly. You should see a nice, strong signal at OSC1 if everything is working.
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