The other question to ask is....have they worked in the past? Or is this a new design.  Could be the crystal might be series cut instead of parallel cut? Wrong caps?
   
  But I'd go with Jan-Erik....do you have the chip configured for the right type of osc.

Jan-Erik Soderholm <jan-erik.soderholm@telia.com> wrote:
  Marty Robertson wrote :

> My company just got in a 
> batch of boards with 18F2520's on them. 
> They seem to work fine with the internal
> oscillator, but with the external oscillator there seems to 
> be no output. I checked with a scope and it is not oscillating.

What did you do to change the *config* of the PIC from
INTOSC to LF or HS crystal osccilator ?

> The crystal is connected exactly as suggested in the 
> datasheet. Where else can I look to find this problem?

Again, what was changed in the *config* ?

Regards,
Jan-Erik.



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