Hi Russell, I had not thought about doing that.=20 In a few moments, I will try to ground all the pins as your suggestion and return here to tell the result. Marcus -----Mensagem original----- De: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] Em nome de RussellMc Enviada em: quinta-feira, 22 de novembro de 2018 05:34 Para: Microcontroller discussion list - Public. Assunto: Re: [PIC) 16F887 - strange behavior > > From: piclist-bounces@mit.edu on behalf of=20 > pp5ms > Sent: Wednesday, November 21, 2018 3:14 PM > To: piclist@mit.edu > Subject: (PIC) 16F887 - strange behavior > > During these tests and new firmware versions, the hardware virtually=20 > stays on all the time, or when I turn off and on to test the system=20 > startup, it is a few minutes without power. > Five days have passed that something happened that I only noticed later. > > This MAY be due to an internal node being charged via invalid pin=20 > voltages during shutdown. eg several pins may be held at 5V initially and decay to zero over different periods. As one decays faster than the other an interna= l junction is forward biased and stores charge in an insulated node that causes havoc. Unusual but not unknown. Test: With power off in the fault state, short all pins to ground with a conducting bar. If you can short many or all at once to ground it's good, but even running van earthed wire along the pins can help. *IF* this works, look at the circuit for conditions where pins may be illegally biased during shutdown or startup. I have seen this and similar happen on a number of occasions. Russell McMahon -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .