Similar problem as in the previous discussion: VDDR = 1.67 V < 1.80 V (min. required supply). I can't start flashing, probably CC2640 stays in power-on reset. External reset is not pulled low, DCOUPL=1.27 V is correct.
Looks like the DC-DC is not switching (no edges on DCDC_SW). Removing the inductor for LDO mode didn't help - same low output voltage.
24 MHz crystal is correctly placed, VDDS=3.0V. There are not too many GND vias around the VDDR capacitor, but can this block operation completely? Anyway, LDO mode should work.
Is there any requirement on the DIOs during start-up?
