on/off switch help please

**jash7** · 08-21-2008, 12:22 AM

okay well i had a car pc in my car for a while that was based off of a desktop pc. it always seemed underpowered and then one day it became unable to boot.

anyway, i have recently been given an old ibm thinkpad T20, and i am wanting to use that in stead of the desktop pc. my only problem is trying to make my old on/off button (which i have already interfaced into the car) work with this "new" laptop.

i tried taking a look on the insides of the pc, but what i found when i removed the keyboard is that all of the buttons (keyboard and left and righ click too) are interfaced into a single chip. heres a picture of the chip thing i'm referring to. it's in the center of the black plastic piece. on a second thought, it might not even be a chip at all haha i'm really not sure i don't usually mess around with laptops.
http://www.xmission.com/~bmidgley/t20/t20-b.jpg

i was thinking maybe i can find two of these leads on the chip that when connected cause the machine to turn on but i am afraid of doing any damage.

so my questions are:

is there any other, easier way to do this?
will this even work?
does anyone have any experience with this?

all ideas will help.

**greatwhite** · 08-21-2008, 01:29 AM

Well, I can't really tell by you picture which "chip" you're talking about (the blue one I assume), but the button has to connect somewhere. You need to find out what it connects too and splice in there. I somehow doubt it is connected directly to the "chip", but I'm not that experienced with think pads.

Another alternative is to buy a docking station for the thinkpad that has a power button and hack into that (ebay is one source for this older stuff). As a side bonus, it will allow you to easily pull the laptop out of the car to work on software in the comfort of your house.

Just a couple ideas............

**greatwhite** · 08-21-2008, 01:39 AM

This is a bit more revealing:

It appears the power button is connected to the board through the multipin connector on the back of the keyboard. You need to find out which circuit trace it is and wire in there. Or chop open the surface around the button to get to a useable/solder-able set of switch connectors.

It appears the docking station/ port replicator for the T20 has a power button also:

This would probably be easier to figure out/hack into that the circuit traces on the keyboard connector.

Your choice...........

**jash7** · 08-21-2008, 12:35 PM

thanks for all your help. i'll do some more exploring and let you guys know if i find any more helpful info.

**jash7** · 08-21-2008, 11:28 PM

okay well here's what i found out. under the button there is a small metal contact. with even the slightest pressure on that contact turns the pc on. i tried grounding the contact but nothing. any other ideas?

**greatwhite** · 08-21-2008, 11:44 PM

pictures would help...........

**jash7** · 08-22-2008, 01:16 PM

unfortunately i do not have a camera or even a camera phone. it's just a small metal circle under the rubber button. i also tried touching that with the metal underneath the keyboard as shown in greatwhites post earlier. still, this did not make the laptop turn on.

**jash7** · 08-23-2008, 04:32 PM

anyone?

**Rob Withey** · 08-23-2008, 05:20 PM

Originally Posted by jash7

it's just a small metal circle under the rubber button.

One metal circle, or two concentric metal circles? Or fingers in the circle? Or two circles on two plastic sheets slightly separated.

Originally Posted by greatwhite

pictures would help...........

Originally Posted by jash7

anyone?

We're guessing without pictures. Usually there are two contacts involved under the rubber button.

**jash7** · 08-23-2008, 06:23 PM

well i figured the small metal piece is a contact and when it touches something the pc turns on. but i can't figure out what it's touching. haha this is killing me.