Thinkpads Forum

Hi
I have for project to install some of my T400 hardware (mostly the motherboard/display) into a separate case/chassis without using the laptop keyboard.

I didn't expect to have this problem, but the power on button is physically on the keyboard and wired through a small ribbon cable. I've tried identifying which pins off this ribbon cable would be wired to the switch but no success so far.

Would anyone know which contacts need to be shorted in order for the motherboard to boot? I suspect it is just like desktop motherboards where two pins need to make contact temporarily for the system to power on but I am not positive it is the case for that T400.

I've done similar things with other laptops but every time it had its own power button which was easily rewired/reused for the project.

I cannot install the whole keyboard in this project.


Any pointer will help!

Thanks

Powerswitch is pin 19 on the keyboard connector (on the motherboard).
Pins 21 and 23 next to it are not connected, that's all I can say.
Don't know on which side of the connector these (odd) pins are.
All the (even) pins are along the other side.
Pins 43 and 44 go to GROUND.

http://forum.thinkpads.com/viewtopic.ph ... 12#p742212

Momentarily ground pin 19 of the keyboard connector to system ground and that will power up the laptop.

Thanks
Yes I found this thread and actually just tried. and the system is not booting.
I am not sure if I have enough components connected to the MB though.

Right now (during my test) I only had the monitor and the AC adapter. I added the RAM but still nothing.

I am sure I have the pin correct (19), I used the broken down ribbon cable to solder a wire on the other end (the contact points are larger than on the MB connector side). Checked everything with a multimeter and my wire makes good contact with Pin19.

you mentioned pins 43 and 44 - they are connected to nothing on my connector obviously since the keyboard isn't plugged in.. Should I wire them to the ground? I mean do I have to?


thanks guys

well looks like if I don't have the keyboard I need to drop the ribbon cable as well. (probably some internal wiring)
I just tried doing it without the ribbon cable and just a wire and it boots up.
so that's my explanation...

too bad, that ribbon cable made for an easy way to solder a wire.

I believe that if you are using the original keyboard connector that's at the end of the ribbon cable which normally goes to the keyboard, then pins 43 and 44 and NOT part of that cable. If I'm not mistaken, the keyboard connector on the side that's part of the keyboard assembly is only a 40 pin connector. If true, then system ground is on pins 31, 34 and 36 of that connector.

the connector that goes on the MB has 44 pins. However, pins 43 and 44 of that connector do not have a physical contact point at the other end of the ribbon.
Anyhow I will have to find a way to solder a wire on the female connector that's on the MB. Any tip in that regard?

http://www.kawakami-ca.com/images/t410_ ... wer_up.jpg

If it were me, I'd see if some wire-wrap wire (30 gauge) would fit inside the through-hole and then solder it down. You'll need a low-wattage, very fine tip soldering iron to do the job and the thinnest solder you can get (0.015" diameter works great if you can find it; 0.025" should be the largest you should consider using). Ground can be tapped at one of the four corners of that connector (i.e., pins 41, 42, 43 and 44) where the relatively large metal frame of the connector is soldered to the motherboard.

thanks Ray
I'll give this a try tomorrow, ordered some 30AWG and .015 solder.
these are certainly tiny holes!

are you apposed to getting a proper KB for this laptop? I have many used ones sitting around that work that I can sell for $10 (inc shipping)