I have an Onyx 550 showing no signs of life (light ring on power plug doesn't even light). Swapping in a known-good logic board confirms that something on the board is the problem. The C1 capacitor rattles when I shake the board, so I'm thinking it has dried out and simply replacing that might fix the problem. Anyone know the full specs of the C1 capacitor? Some specs I can read/see on the cap: * surface mount design * Rubycon (manufacturer) * 220 uF * 35 V * 105 degrees C (apparently the top end of the rated operating temperature range) * NO144 (not sure if that's exactly what it says or what it means) * 10 mm diameter and 10 mm high * presumably this is an aluminum electrolytic type If I have all that right, then it narrows down the selection of caps at Mouser pretty well. See http://www.mouser.com/Passive-Compo...D/_/N-75hqx?P=1z0wrjqZ1z0sq5yZ1z0scm8Z1z0rxa7. But there is at the least a question of the low-end temperature rating, and beyond that I would be happy to have someone confirm my overall assessment above.