T41 Keyboard keys not working - UIOP

[MattSau]

Hi there,

First of all I'd like to say I've tried a few things already mentioned in the forums

I have a T41 with 4 non-responsive keys (U I O P). I've searched around and tried many things without success.

Background
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Like most people with keyboard issues - it started with replacing some 'other' part in the machine. The fan became noisy so removed it to check the part number. I'd also been playing with trying to get 2 1gb sticks of RAM to play well together (without success). The RAM remaining in the machine is in the slot under the keyboard.

After one of the several times the keyboard was removed and re-fitted, the UIOP keys stopped working. I'd already ordered a new fan from eBay so reluctantly ordered another keyboard (used) from eBay - assuming I'd fried or bent something in the process.

What I've tried
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The new keyboard came first so fitted that - no dice. Exactly the same behaviour (pretty unlikely both would have the very same non-functional keys?). The motherboard keyboard connector doesn't show any signs of wear or bad connection.

The fan then came, so ripped everything out again. New fan works great - quiet. Then tried both keyboards again - no dice.

I then tried disabling num lock in the bios (curiously I couldn't get numlock to go on or off on the keyboard anyway), uninstalling the keyboard driver (Windows XP), removing all other input languages etc. All exactly the same after reboot.

Tried PC-Doctor diagnostics interactive keyboard tests, UIOP still not registering.

What Now?
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I'm loathed to just give in and basically toss the machine and get a new laptop, but I can't really invest much more time or money into it just for fun!

Does anyone (with hardware experience) have any practical thoughts on what to try next (if anything)? I think I've proven it's not a software/driver issue (Windows), and it's unlikely (but not impossible) that both keyboards have the same fault. I guess if there's a short somewhere on the motherboard, the new keyboard could have been fried when I first put it in?

Anyway - enough talking! Any thoughts gratefully received.

Cheers,
Matt

[Harryc]

If it was a PC-Doctor DOS boot CD, that runs at a very low level and catches hardware failures. My opinion is that you need a new systemboard. I would examine that internal keyboard connector with a magnifying glass first though ... also see if you can wiggle or press down on the connector (while the laptop is powered up) and make the keys work.

[MattSau]

If it was a PC-Doctor DOS boot CD, that runs at a very low level and catches hardware failures. My opinion is that you need a new systemboard. I would examine that internal keyboard connector with a magnifying glass first though ...

Thanks Harry for the quick reply - I must admit I was leaning towards the keyboard connector as soon as the second keyboard had the same issue, and had thoughts of somehow testing it, but the contacts are pretty small and I've got no technical info on what connects to what. The connector's pretty close to the RAM slot too, and I'm wondering whether I was maybe a little sloppy one time I was removing/replacing the RAM or the keyboard connector - i.e. frying something small, but important on the board.

I'm presuming I can remove pretty much every screw to get the system board out (so I can inspect the connection to the board itself) - beyond that I think I'd have to give up, and this machine would become yet another 'server' I remote into!

Thanks again,
Matt

[Bibin]

While the plug on the board may look fine based on your results it sounds as if it has had some of its solder joints go cold. Reaoldering it may help.

[MattSau]

Thanks - I'll try and get everything out, so I can check the connections. At least if I can see the tracks of the circuit I might be able to trace to other components too. Will post results over the weekend.