It's a convertible tablet with a detachable keyboard. There are various kinds of keyboards: (1) a desktop docking station that I use on my desk at work (I have a USB keyboard, trackball, wired ethernet, and an additional display), (2) a thin folio keyboard that is very lightweight, and (3) a heavier keyboard that also has a spare battery. The thin keyboard is a little less nice to type on and feels delicate, but I use it when I don't want to carry extra weight. I usually use the heavier one because typing is nicer. It basically makes the computer into a laptop.
A few weeks ago, the computer started having issues charging the keyboard's battery. Worse, it refused to boot at all! It was quite badly stuck and would not even show the BIOS Dell logo... Uh oh.
After looking around the forums, I found that the thing to do was to open up the machine, disconnect the battery and the RTC battery (marked), and
then hold the power button for a few seconds. Upon reassembly, this procedure seemed to restore life to the machine. Plugging the machine into its dock or the folio keyboard seemed fine, but plugging in the heavier keyboard killed it again! Figuring that the cause was the keyboard, I ordered a replacement.
The replacement seemed OK except that the spare battery was not detected. This is apparently a "design feature", and requires you to charge the keyboard separately first. So I did that, and then trouble struck again... When the keyboard battery was charged, it bricked the machine again! Uh oh... evidently the keyboard was not the problem, even though it seemed otherwise.
More searching of forums revealed that the problem is actually that the pins on the bottom of the tablet had retracted into the case and therefore where not making good contact anymore. The dock uses a separate connector, and is therefore unaffected, and the folio keyboard connector pins are apparently longer. Since I had to take apart the machine again anyway, I followed the forum post's advice and removed the rest of the case to expose the pins. This being a modern-ish computer, not only are there screws (with standard heads, thankfully) there are also many delicate-but-stiff spring clips. I think I managed to avoid breaking them!
It was straightforward to very delicately and gently tap the pins using my staking set from the inside of the case ...
... until they slightly emerged from the bottom of the case as they should.
I reflowed the solder (using lots of flux) around the connector to make sure I hadn't accidentally broken any connections in the process.
This seems to have fixed the problem, as I am posting this using the keyboard and both batteries are indeed showing up as present!
Update (4/24/2017):
When I got to work, the desktop dock didn't work... and later the machine flaked out on the keyboard again. Argh. It turns out that the two ribbon cables for the daughterboard at the bottom of the case under the battery (one for the dock, labeled as such on the cable and "DOCK 41 PIN" on the board, leftmost, and the other labeled "LCM" on the cable and "DOCK 45 PIN" on the board, next to it on the right) needed to be reseated. The cable displacement was not visible (to my unaided eyes) but was visible under a 5x loupe. In any case, reseating both cables seemed to fix it. Indeed, the loose ribbon cables might have been the problem all along!
More links about this problem:
- Reseating internal ribbon cables: http://www.dell.com/support/article/us/en/19/SLN291143/venue-11-pro--5130--tablet-keyboard-does-not-function-when-docked-on-a-travel-keyboard?lang=EN
- Detailed debugging thread: http://en.community.dell.com/support-forums/mobile-devices/f/4586/t/19568048
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