Thinkpads Forum

We've got a 600x thinkpad with a broken lid switch. I've got the repair manual but it doesn't give specific information on how to remove the sub-card. Also, would appreciate getting information on how to by-pass the lid switch.

Thanks.

http://www.rkawakami.net/ibm_600x/sub_card/

The Hardware Maintenance Manual should have the instructions on how to remove the Sub Card (link provided at the web site above). The switch can be bypassed if you connect (short) the NC and COM terminals of the lever switch.

edit: I should clarify that you need to remove the switch from the Sub Card and then short the pads (or connect a piece of wire between) where the NC and COM (C) terminals were soldered to the board.

Thanks.

I removed the sub-card. Is the com terminal the middle one? Not sure which one is the n.c. (they're not labeled).

Is it possible to just short the terminals on the switch? (The lever is broken off).

Yes, the common terminal is the one in the middle. Take a close look at the fourth and fifth photos on my site (under the "Comparison and modification" title). Position the switch you removed as shown in the photo. The switch on the right is the original one. There's "NC", "C" and "NO" stamped on the side, from left to right. I would remove the switch and connected the holes on the Sub Card which correspond to the NC and C terminals. Those would be the one in the middle and the one closest to the "S1" printed on the Sub Card.

The reason I would recommend that the switch be removed is in the case where you close the lid, then all three terminals could be shorted together (assuming that the lever gets depressed) and I don't know what that will do to the Sub Card (or the rest of the system). You will of course lose the ability to close the lid and automatically put the system into standby or hibernate. Actually, I just re-read your post and if you say that the lever is broken, then that's the case already. Also, the switch could be broken such that it is making the contacts between the C and NO posts (the position it would normally be in if the lid was closed). That's another good reason to remove the switch since you probably don't want to short all three together.

BTW, both Mouser.com and Digikey.com appear to have the Omron D3C-1220 switch in stock and they also will sell just one. Price is just over a $1 but the shipping will kill you .

Thanks again.

Actually, there's practically nothing left of the top of the switch. The plastic cover is broken off and there are 3 terminals sticking up. The part that has NC, NO, and COM is gone as well as the lever.