Measure +5 supply with _scope_ right on the PIC Vcc pin.
( no pulses above specififed in 628 datasheet supply voltage )

It is reasonable to use 7805 regulator if you didnt do so yet.

Question :
Anybody heard of PIC heating up not being properly reset
or when no clock is applied ?



Jason wrote:
> 
> MCLR is going through 100k to Vcc.  There is no reset switch.
> 
> I just tried powering it again to take some voltage measurements with the
> first blown chip.  It got super hot again, worse than before since I wasn't
> feeling it and I didn't notice until I started smelling it.
> 
> I know for sure that the clkin pin was not shorted to anything this time
> though.
> 
> If 2 outputs from the driver transistors get shorted, it should not cause a
> problem for the pic; just the transistors will get hot, right? (I'm trying
> to narrow down where to look)
> 
> Jason
> 
> ----- Original Message -----
> From: "Jinx" <joecolquitt@clear.net.nz>
> To: "Microcontroller discussion list - Public." <piclist@mit.edu>
> Sent: Tuesday, October 18, 2005 2:30 AM
> Subject: Re: [PIC] Dying PICs
> 
> >> I would recomend to place small resistor i.e. 200 OHm is
> >> series with PIC inputs connected to outside 0 to 5V signals
> >> to limit ingoing current
> >
> > That is recommended by MC in their circuit for taking /MCLR
> > low with a reset switch. Jason, do you use a reset switch and,
> > if so, does it take /MCLR direct to 0V ?
> >
> > --
> > http://www.piclist.com PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
> >
> >
> 
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist