Just another curiosity trip. After all these years of proudly using Lenovo Thinkpad notebooks with docking stations at work and at home, I have always wondered how much hardware these docking stations actually add or contain. Are they just stupid port replicators, adding ports wired 1:1 to that large docking connector, or do they have their own brain?
Let's find out and get right into it. Excuse the image quality, this was done on the fly with little time.
The subject of this blog is a Type 4338 ThinkPad Mini Dock Plus Series 3 with USB3.0, Lenovo part number 0C10039 and FRU part number 04W3939. Used this with my W530 notebook.
To get started, undo five screws at the bottom side. The two dotted arrows indicate two more screws on the connector side of the unit which also need to be removed.
The topside does not offer any screws. Nothing is moving much unless a notebook is actually placed on top of it. To get the connector cover off, push the top left and right hooks inwards and lift it out.
This is how the top cover looks inside, the both hooks are indicated by yellow arrows. Note that the three tabs on the other side are what is coming out last in disassembly and getting in first when you put it back together.
Once the top cover is gone, we find two springs and four more screws (around the connector) which we need to undo to get the shell open.
Oh, did I mention there are two more screws at the backside where the connectors are? The first is above the Kensington lock slot.
The second is in the USB connector section:
We can now begin to separate the top and bottom gently. Notice there is a small ribbon cable for power and lock status that needs to be disconnected. The end of the cable will stay connected to the main PCB in the bottom part.
On the other side of the unit are the microphone and headphone connectors. The upper part of the housing needs to be cranked over them to come loose:
Be careful in this step so you won't damage the connectors or anything around them.
The active circuitry is all in the bottom section, all shielded perfectly Lenovo-style. To get the shielding metal sheet off, remove five silver (yellow arrows) and three black screws (blue arrows):
The metal shield is sitting tight around the notebook connector so you will need to pry a little there. You will also need to undo the nuts holding the VGA and both DVI ports in place. It is indicated in the next picture where the sheet is already gone:
We now see the backside of the PCB beneath the black isolation sheet so it is actually working in upside down position. All the electrons are gonna fall out!
A little wiggle here and there, and out comes the board!
So that's a bit more circuitry than I expected!
The DVI/DisplayPort pairs each have two dedicated controlling ICs:
U104 and U103: Parade PS8312 – 1:2 DP to DP/TMDS Demux
U101 and U102: Texas Instruments SN74CBT3257 4-Bit 1-Of-2 FET Multiplexer/Demultiplexer
Now for the audio interface:
The single USB 3.0 connector:
A little below that:
U501: Single Lane USB 3.0 Redriver . (Rev. A) - Texas Instruments (PDF warning)
So far this is all firmly in the hands of Texas Instruments. Well, why not.
Near the Ethernet connector, we find this fellow:
U111: SMSC (Microchip) USB2517 USB 2.0 Hi-Speed 7-Port Hub Controller
Each of the the paired USB 2.0 connectors are supplied by this combo:
U106, U107, and U108: Texas Instruments TPS2052B Current-Limited, Power-Distribution Switches
The Ethernet transformer/controller (I never knew this exists as an all-in-one module):
T101: M-Tek G24101SKG (can't find any data sheet on this one, sorry)
Random part probably supplying the DVI/DisplayPort section:
U8: ST ST1S10 Monolithic synchronous step-down regulator
Close to it we find:
Q12 and Q13: ON Semiconductor FDS6690A Single N-Channel, Logic Level, Power Trench® MOSFET
And further below:
U9: 418 1225 G000 (sorry, unknown part)
So what is the docking station? It seems clear that most functionality depends on the notebook. It adds a large USB hub, a USB 3.0 port, an ethernet port which is mutually exclusive with the one built into the notebook, display multiplexers (not a separate video adapter), and an audio amplifier which merely repeats the notebook signals (and is also mutually exclusive with the connector in the notebook).
As there is not much circuitry around the VGA connector, it is probably just passed through from the notebook.
And that's it! Hope you found this interesting :o)
