Finding shorts in boards

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Dec 1 18:56:03 2004

>
>
> I've got a board here with a short between ground and the +5V rail
> (actually not quite dead - I'm getting around 10 ohms between the rails)
>
> Any useful tips for finding the fault? It's a large board, multi-layer,
> lots of silicon on it unfortunately :-(

10 Ohms is not a short! It might even be the right resistance. Have you
tried powering it up?

>
> Are there any particular components that are likely to fail in this way
> that might be found across PSU rails? (decoupling caps, certain ICs,
> crystal modules etc.?)

Most times something shorts (particulalrly a decoupling capacitor) it
goes dead short (<< 1 ohm).

-tony
Received on Wed Dec 01 2004 - 18:56:03 GMT