On Wed, 13 May 2009 07:11:07 -0700 (PDT) jango2
wrote in Message id:
:

On May 13, 4:50*pm, JW wrote:
Let's say you know that a certain point on a data bus has a defective
device that is always trying to drive the bus low; Was wondering if anyone
has any good tricks in finding the defective device, other than
cutting/lifting pins?

Does the bus point show low ohms to ground in cold state?(powered
down). If so, leave a sensitive ohmmeter connected to it, hover over
each device feeding the bus with a hot air blower. When you see a
sudden pronounced change in ohms to ground you're hovering over the
culprit.
Jango

I always check for that - if I see a low resistance to GND when power is
not applied, that's an easy one. I have a Toneohm with a 200m Ohm range.
Also useful for finding etch/solder shorts. Thanks, though.