mart256:
Jcolombo:
Thanks to all for quick response!Just tried it with another new 21-22 pf cap which I checked with a precision multimeter (and with REL button)... but the board stopped working again... then so I decided to remove it again and use the board without it !
Anyway, I left undisturbed with Crossroads's opinion...
my concern was could damage the microprocessor or same fault but apparently work even though the cap values ??are very different.thanks
JorgeSometimes there is parasitic capacitance between the crystal and GND, and this added to your 22nf caps prevents the microcontroller from starting.
It happened to me once, with a homemade Arduino. I removed one of the 22nf caps and now it works like a charm (with just 1 cap 22nf). Anyway, check the delay function is working properly (measure the time and check it has correct timing), because less capacitance on the crystal may acelerate (or slow? not sure) the clock.
Can't check that was as the crystal is used for the USB serial converter not the mega chip one programs.