T420 4177R3U Hardware/Dock/Keyboard Problem? [ Edited ]

[lavinsr]

I have a new 11/14/2011) Lenovo T420 with Windows 7 Pro. I am having a problem with the laptop when in the dock Model 4337.  I do not know for sure but suspect my built-in keyboard may be causing a strange situation which manifests in two ways:

First, if I mouse click a desktop icon when the lid is closed as though to start a program a dialogue box comes up (like 20 to 25 boxes in an overlay pattern - one dialogue box on top of another) asking if I am sure I want to move the icon to the recycle bin.

Second, when using MS Word or Google docs and when editing a document the cursor begins, at random, and in an uncontrollable fashion, to delete text as though I was holding down the "Backspace" key or the "Delete" key.  This does not happen all the time but not knowing when it will happen is un-nerving.

I ONLY have this problem when the laptop is in the dock and the lid is closed; for example this problem never happens when using my laptop without an external mouse or keyboard (never happens when using the trackpad and built-in keyboard when the laptop lid is open). The external mouse was recently replaced and I had the problem before that change and after as well, same for the USB keyboard.  I have no viruses or bugs that Norton, Kasperky, MalwareBytes, SuperAntiSpyware, etc. can find; I really don't think it's a virus since this problem ONLY happens when in the dock.

The dock is a type 4337.  My guess is that the lid is putting pressure on the keyboard or on the keyboard ribbons that run under the laptop keyboard.  Is it possible the lid, when closed, is changing input device bahavior; for example pressing on the "Backspace" or "Delete" key(s).

Thanks in advance for any help!
Steve

Optional Information:
Computer OS: Windows 7

[ExJamJus]

@lavinsr,

Try connecting the keyboard and the mouse to the laptop directly (without the dock), does the problem happen?

You can also try to turn off the screen, set laptop to do nothing when lid is close, plug in USB mouse and keyboard to laptop directly and plug the external monitor directly to the laptop then try and see if the problem happens without the dock.

If both mentioned above does not happen without the dock, you might want to contact support to get the hardware checked.

//JamJus

[lavinsr]

JamJus;

Thank you for those suggestions.  I understand that there are some known problems with the ribbon cables that connect to the T series keyboards and I have opened a case with Lenovo support.  The PC is used for legal docs and I am very concerned about testing it any further with documents; just do not have the time to troubleshoot this but your recommendations do make sense and I appreciate them.

Perhaps the lid applies pressure, when closed, to the ribbon cables and/or DELETE or BACKSPACE keys(?).  Thanks again!

Steve

[ExJamJus]

Steve,

Personally I haven't opened a T420 before however the keyboard ribbon does not go anywhere near the lid (based on the T61p or T410 which I've opened before)...

Therefore I doubt it could be caused by the lid but I guess the techs at the depot would need to check that out.

Word of advice, do backup your docs if there is a need to send the laptop in.

//JamJus

[jmhorne]

I have been experiencing a similar problem on my X201.  I usually only use my computer docked, but I can confirm that the random and uncontrollable text deletion occurs even when the lid is open.

I recently updated the BIOS on my machine, so I am wondering, lavinsr, if you also recently updated your BIOS.

[Kicker774]

We've seen a good quanity of these cases in our new T420 units.

Run the latest BIOS (http://support.lenovo.com/en_US/research/hints-or-tips/detail.page?LegacyDocID=MIGR-77167) to disable the keyboard while the lid is closed.

There are antenna wires that run underneath the keyboard and they are not always laid flat and smooth in their notches.

If the problem gets worse your keyboard ribbion could be getting pinched reulting in those eronious keypress events.  If you see that happening you'll need to give Lenovo a call and get it swapped out.