At 10:43 AM 10/6/97 -0400, you wrote:
>About 5% of my production run is having
>problems with start up of the oscillator.  I am
>using a 4 MHz parallel crystal Digikey part number
>X006-ND, with a pair of 22pf NPO ceramic chips
>on either side to ground.  Local bypass is good.  At first,
>because the board is not accessible to customer, I had
>been leaving the flux on to save time and environment.
> For normal resin flux, this didn't seem to matter, but I recently
>switched to organic water soluble flux, and I thought
>I would pass along my tentative observation that this stuff
>has got to be thoroughly washed off.
>
>But even with a clean board, the start-up problem
>persists.  Has anyone done any comparison between
>quartz crystals and ceramic 4 MHz resonators regarding
>reliability of start up?
>

I have heard that making one of the caps on the xtal pins (I think it was
the one on the pin OSC2) larger than the other by a few pF sometimes makes
startup more reliable.

I have not tried this, just heard it.

Sean



Sean Breheny,KA3YXM
Electrical Engineering Student