Re: Power on issue solved on my QCX :-)
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Having to reduce C47 to 10uF only means the problem is somewhere else, classic case of trying to compensate the symptoms I believe.
I don't know where the problem lies, but more measuring is the way to go. Put a scope on the cap and one-shot the power being turned on and see what's going on ? Check that the crystal starts up every time, it's not a too uncommon problem and sometimes it's the crystal itself, sometimes the connection or even too high/low capacitance so the loop gain is too low. A sneaky way to test the crystal could be to lightly tap it when it has not started up properly, intermittent connections and such in one go. Not really sure how the AVR does the startup timing on the crystal, if it's the internal watchdog that times this... so could be pointless starting it up some time after the power has been applied. Either way you should be able to measure or hear (tune to it with a radio) the crystal oscillate.
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Daniel Ekman SA2KNG