I recently dropped my N800. I notice it did not detect any memory cards in the internal slot. I could access them in the external slot. I tried the remedy involving the missing magnet on the battery door, but the magnet was there. Being that my N800 is out of warranty, I opened it up to look for any other signs that might contribute to this problem. That's when I noticed there appeared to be something missing from the board(right where the magnet sits when the battery door is closed). After comparing mine with a picture of the insides of a normal N800, I noticed what had to be the magnet detector was missing. Is there a way to tell the device to bypass this function and enable the card slot anyway?

Yes. It can be done by changing omap mmc driver in linux kernel. The simplest solution is to comment lines 912,913 here
http://mxr.maemo.org/diablo/source/k...mmc/omap.c#908
Without those lines mmc driver keeps monitoring card change even if card door is not closed. This is not ideal but it allows you to access the card (and mount it manually to /media/mmc2)
I have done this and it works. The extra polling might (slightly?) affect battery life.

Alternative is to redefine mmc_omap_cover_is_open
http://mxr.maemo.org/diablo/source/k...mmc/omap.c#286
to return values you wish so cover open/close events are simulated. The easiest is probably to hook it to card door of second slot (by hardcoding slot value id) so both slots are checked when one door is opened/closed. I have not tried this.