Duodock won't take in duos

[d3jsp]

Came across a duodock that looks to be in good shape from the board but won't take in any laptops, no clicking.
Measured voltages across the power supply which seems fine with yellow wire being exactly 5V and blue wire at 21V

Any idea why it won't take in a machine?

 

[beachycove]

I’d take the lid off in order to see what is happening when a machine is slid in. It has been a few yeas, but I seem to recall that there are mechanical switches that trigger the action.

 

[Trash80toHP_Mini]

The gears in the latch mechanism sometimes get chewed up. Take a look at that.

 

[Byrd]

Springs too, and check it’s unlocked.

 

[d3jsp]

Yeah, it seems to be unlocked and I tried using the eject switch but nothing happens. Is there a 12V line from the power supply that I can check also?

 

[jmacz]

I've been working on a duo dock I received recently. The mechanism on mine does work and when the Duo is all the way, the dock works. But the auto suck in mechanism is not great on mine hence I've been messing with it.

For your issue, is the motor not moving at all or you hear the motor doing its thing but the little clips that attach to the Duo don't move or ?

If your motor doesn't do anything, there's two things to check... there's a physical switch near the FPU slot (near the nubus connector) and if that switch isn't depressed, the logic board doesn't think the latching mechanism is installed and/or something's wrong and won't enable the latching mechanism. When the logic board is installed, that switch should be pressed down by a piece of metal and kept down.

Another thing to check is there's an optical switch right next to the physical switch. As the Duo is slid in, there's a sliding piece of plastic in the docking bay that moves backwards and cuts the optical beam on this optical switch. That tells the motherboard to start the motor and pull the Duo in. You may want to use a card or something to block the beam of light in that switch to see if your motor does anything.