I'm attempting to repair a Duo Dock 1, which came with a Powerbook Duo 270. The 270 works fine on its own and in a Duo Dock II.
The Dock originally had the "click of death", a rapid ticking sound whenever it was plugged into mains power. Going off this site, I replaced the two 35V/100uF capacitors (the site refers to C28 and C24 and 25V/100uF caps, mine had 35V so I replaced both). To my delight, the power supply now must work, as it accepts and ejects a Duo smoothly.http://lowendmac.com/pb/duodock-tick-of-death.html
... however, that's as far as I can get. When powered on in the Dock, the 270 only emits a green LED that comes on once then off again, kind of like a GLOD but this usually only occurs on the Duos when running independently. There is no chime or anything else. Google-fu reveals nothing. The Dock internals look in good condition.
Any pointers from here?