Rick,

The hum you hear is due to the 78S40 switching regulator inside
Picstart+. It _should_ be protected against excessive current drawing, but
I suggest you don't stress it any longer.

Ale

On Thu, 25 Mar 2004, Rick Regan wrote:

> I know there have been many "fried PIC" stories on this
> list but I don't know if I've seen one like this.  Due to
> some temporary mis-wiring (can't say I know exactly what I
> did!) the PIC 16C745 on my board got extremely hot.
> After correcting the wiring the chip "worked" (at
> least the functions I was using).  However, it still got
> hot and I discovered it was drawing 250 ma of current (should have been closer to 15 ma).
>
> The interesting thing is that when I read the contents of
> the chip using a PICstart+ I heard a noticeable high-
> pitched hum.  Can you harm a programmer with a bad chip?
> (please say no).
>
> I'm also curious about what could have gone wrong with the
> chip such that it still appeared to function.
>
> Needless to say, I've scrapped the chip.
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.
>

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