Duo Dock repair - "click of death" fixed, now GLOD!

[Byrd]

Hi,

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?

Thank you

JB

[Mark97062]

Many thanks for this post and the link to Sean Cleary's article! I was able to revive two dead duo dock power supplies by replacing the defective capacitors.

Regarding your dead dock, does the fan start when you press the power button on the back of the dock? Did you replace both c28 and C24? Did you try removing the battery in the Duo while in the dock?

-Mark

[Byrd]

No fan or life apart from a green LED sadly, and I replaced both C24 and C28 capacitors. I suspect the Dock motherboard itself has died.

The 270c, battery removed, works fine in a Duo Dock II!

Glad to hear however you got a couple of faulty Duo Docks working. But much fun cracking open that power supply, is it?

JB

[Bunsen]

The Duo Dock manual from Service Source suggests measuring the voltages for pins 5 and 7 on the power supply-to-logic board cable. They should fall between the following ranges:
• Pin 5 (yellow wire) 5V + or - .5V
• Pin 7 (blue wire) 20V + or - .5V
If voltages don’t fall within the above ranges, replace the power supply.

For more info see:
<snip>

[Bunsen]

While I appreciate the fact that you're being helpful, Apple's service manuals are still under copyright, and they are known to enforce it. As such, we cannot permit download links to their manuals.

Thankyou.