The micro SD card is not retained anymore, thus the options are :
a) trash away the Raspberry and buy a new one
b) try to repair it
Originally I though to replace the micro SD card slot but then I found a very easy workaround.
First of all, the micro SD card slot is the one with a spring to facilitate the expulsion of the SD card.
Apparently, especially on the Raspberry Pi B was quite popular.
Now is is not used anymore because the huge number of units that after a while had problems, like mine.
The typical problem of this slot is that the "retain" state fails and the card is ejected.
So the workaround is just to remove the spring from the slot.
I did it and voila', the Raspberry Pi is back alive :)
Removal springTo remove the spring is quite easy.
With a small plier lift the spring holder, then move the mechanism few times with a very small plier or a small pointy thing.
After a while the spring will become visible on the opening.
Capture it with the plier and remove it.
|The Pi with the broken micro SD card slot|
|Lift the small metal tongue as indicated by the arrow.|
Then using a small pointy thing, move back and for the slide mechanism until the spring become visible.
Remove the spring with a small plier.