T23 Volume Keys not Registering

[Harryc]

I have a T23 that does not respond to the volume up/down, and mute keys. I can raise and lower the volume manually from the taskbar icon, but the keys don't do anything. If it matters, the Hotkey utility is installed, and the OSD works because it appears while doing brightness adjustments. Am I looking at a new keyboard here? All other keys work, and all PC-Doctor tests pass, including the interactive keyboard test, but unfortunately that test does not allow one to test the volume or 'Thinkpad'; keys. I can't recall ever seeing this problem on a Thinkpad before, the volume keys usually just 'work'.

[RealBlackStuff]

"Keyboard customiser utility" comes to mind.
http://www-307.ibm.com/pc/support/site. ... MIGR-44185

[Harryc]

RBS, good thought, but that is not it (it's installed). It's almost like those keys are dead. I think I'll pop the keyboard this afternoon and inspect/reseat it.

[Harryc]

No good on the keyboard reseat, those keys are still not registering.

[tdlpad]

I had the same problem with a 2647-4MU. I replaced the keyboard, made sure the correct software was loaded and reloaded. Was totally frustrated and finally gave up and got rid of it. Have had several other Thinkpads with no similar problem.

[Harryc]

Keyboard was replaced, same problem. Swapped hard drive into another T23 and volume up/down/mute worked fine there. So, this looks like a systemboard problem.

[RealBlackStuff]

Does this shed any light?
http://forum.thinkpads.com/viewtopic.php?f=2&t=78815

[Harryc]

RBS, thanks for the link. As I mentioned, I took the entire hard drive from the failing machine and put it in another T23 and volume up/down and the OSD worked fine, so it is not a software problem.

[Harryc]

Some additional data points. I installed the latest versions of .NET Framework, Hotkey utility, Power Manager and Access Connection. I also installed the Access Thinkpad online manual. If I press the 'Thinkpad' button the Access Thinkpad manual pops right up, so I know that key works. I also installed keyboard customizer and assigned the ctrl-up arrow to volume up, and ctrl-down arrow to volume down on an external keyboard. If I use these keys volume up/down works fine and the OSD works fine. Unfortunately this is all on an external keyboard.

[RealBlackStuff]

Could it be that there is dirt in the keyboard connector on the mobo?
Try blowing it out, preferably with some canned air.
And see if you can also blow out the connector on the keyboard itself, just in case some dirt got transferred.
If it's not that, then I am plum out of ideas, other than replacing the mobo.

[Harryc]

RBS, I'll try it...speaking of Mobo's, do you have one for sale or trade?

[RealBlackStuff]

I saw your WTB, sorry, I don't have any at the moment.

[rkawakami]

Harry,

I've updated my T23 motherboard thread: http://forum.thinkpads.com/viewtopic.php?f=28&t=37956

with the reference for the audio processor (AN17000A). May not be any help, but you could look in that area and see if there's any obvious damage. Remove the memory access panel, pull the module next to the front edge of the system and U22 is right there in the corner. The volume control pin is on pin 39. Unfortunately that puts it on the side of the IC closest to the front edge. Volume appears to be controlled by varying the voltage level on that pin. How that voltage is controlled by the two pushbuttons on the keyboard is still unknown to me. Most likely there's another controller which converts the pulses from the switches into an analog voltage that gets applied to that control pin.

Edit: Looks like ThinkWiki has some information... http://www.thinkwiki.org/wiki/Embedded_Controller_Chips says that there's an H8S microcontroller on the T23 motherboard. I can confirm that as it's the larger of the two square chips underneath the "front" memory module. It has (had) a white label with an FRU of 30L2413 printed on it. ThinkWiki also says that the H8S "... controls various low-bandwidth devices such as keyboard, mouse, ...". So maybe it will pay to look around this chip as well.

Coincidentally, when I took a closer look at this "does not turn off" labeled T23 motherboard, I noticed that a chip resistor was sitting at a weird angle next to the H8S. It apparently has come loose from somewhere around in that area. Now I'm wondering if the problem I saw with this motherboard (it would not power off with the keyboard's button), now the donor of some inductors and serving as a test subject for circuit tracing, was due to this missing resistor .

[Harryc]

Ray, I had a good look around U22 (AN17000A) and H8S (30L2413) and I do not see any loose or broken chips or traces. The pins going into both IC's look clean and intact. Thanks for the tip and research.