Finding shorts in boards

[Jules Richardson]

On Wed, 2004-12-01 at 09:43 -0500, Paul Koning wrote:
> >>>>> "Jules" == Jules Richardson <julesrichardsonuk at yahoo.co.uk> writes:
> 
>  Jules> I've got a board here with a short between ground and the +5V
>  Jules> rail (actually not quite dead - I'm getting around 10 ohms
>  Jules> between the rails)
> 
>  Jules> Any useful tips for finding the fault? It's a large board,
>  Jules> multi-layer, lots of silicon on it unfortunately :-(
> 
> 10 ohms means about 0.5 amps -- sounds like a perfectly respectable
> amount of current for a board with "lots of silicon" to draw.
> So... are you sure there is a short, rather than just circuitry?


Hmm, you could well have a point there. There's around 150 ICs of LS-
logic complexity on the board, then around 30 or so more complex
beasties. Perhaps that figure isn't so unreasonable.

If I can work out which pins on the euroconnectors provide power then
maybe I should hook a known-good 5V supply up to it and see if that's
happy powering things...

cheers

Jules