If the chip was made in Katmandu, then the previous thread on pic list of 
"shock the kitty" may apply.

Try probing it  with a non conducting object and see if same thing happens. 
If it does maybe there is a bad solder joint or the chip needs to be removed 
and reinstalled in it's socket.

Or the chip may be heat sensitive and your finger heats it.  A way to test 
for this is to blow hot air from a hair blow drier or a heat gun on the chip 
while it is running. Sometimes is helps to cool down a circuit or component. 
Freezing your finger and then touching the parts is painful because of the 
frost bite.  They make cans of "Freeze It" spray that will put frost on the 
pumpkin.

Once you have found the part that works/don't work, when you heat/cool it, 
then you have found the problem which  may have been an intermittent problem 
and difficult to find any other way.

As a final test on a state of the art board where I once worked, we would 
cover the board under test with 15 mm of sand and heat it with blow torches 
to a cone 4.  Then with a CO2 fire extinguisher, we would blow the sand away 
and make frost on the board.  If the board worked during this test, it would 
pass and be put into the "Minnie the Moo Cow" Speak and Spell Computer.

If all else fails, "Don't Do That!". or put a finger shield over the chip.

Pookie

----- Original Message ----- 
From: "kerri" <kerri1111111@btinternet.com>
To: <piclist@mit.edu>
Sent: Saturday, February 18, 2006 5:59 PM
Subject: [PIC] 2 questions about 18f4550


> Hi,
>
> I have to questions about pic18f4550,
>
> 1. I have noticed that if I touch the top of the ic with my finger
> the usb connection to my computer breaks. Is this normal?
>
> 2. Is it possible to write a firmware for the this pic that will listen
> on all addresses (to enable to write a packet sniffer?)
>
> thanks!!
> -- 

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