Proprietary USB header on D10 (6493)

[Whozit]

The D10 (6493) motherboard has 2 USB headers on it, a common 10-pin header which is connected by default to the front panel (label in the HW maint manual "Auxiliary USB connector 2"), and a proprietary 12-pin (1 removed) header, (label in the HW maint manual "Front USB connector")

I have looked high and low on the web or in Lenovo documentation for a pinout for this 12-pin header because I have a device that requires a motherboard USB  connection. The closest thing I could find was in this thread pertaining to a ThinkCentre A60 (which also has a proprietary 12-pin USB header) but when I did some preliminary tests before I blew anything up I discovered that there is 3.3v between various pins labeled as 'Ground" in that diagram. So that must not be it.

 Can anyone help me out with this?

[erik Community SuperMod · Accepted solution]

welcome to the forum!

this post shows how to use a 12-pin header with an 10-pin device socket.   for ease of reference, here is the image:

simply connect your device in the dark area shown above, leaving the last two pins free.

[Whozit]

Thanks for the quick followup.

So that more or less agrees with the diagram of the ThinkCentre in the other thread I linked, that there is one extra row of ground pins at the 'bottom' of that header.

But when I measured the voltage across the 2 extra ground pins (pins 1 and 2 in the thread I linked previously), I got 3.3v. And when I measured the voltage across pins 2 to 10 I also got 3.3v, despite the fact that both those pins are also both supposed to be at ground potential.

So I'm still a little nervous about this... ;-)

[erik Community SuperMod]

if you follow the key (either plugged or blank) and install the connector on the pins shown in the diagram then you'll be fine.   i've installed devices exactly like this in both my former D10 and current C20.   thinkstations have standard USB header mappings save for the last two pins.

[psuturtle Lenovo Staff]

There's a reason you're seeing 3.3V....those aren't both grounds

The two extra pins on the bottom end of that connector are a ground and a GPIO.  These are used as a presence detect method within BIOS.  When the appropriate device is connected (for example our media card reader) the header on the device has a jumper that pulls the GPIO to ground, indicating to BIOS that it's connected.  When there's no jumper there, the GPIO is normally pulled up to 3.3 so as to not be floating and provide the right input to BIOS to indicate that no device is present.

You should be OK if you follow the diagram Erik posted.  The connector pinout (sans the two pins) are pretty much industry standard.  If  you're still worried, I can try to dig up the actual pinout.