I have a 2DS that I am working on that has a problem reading SD cards. I knows that card is in the slot (which, means the detect pin is working anyway) but it says it can’t read the card.
Here is what I have done so far:
-Tried SD card in another 2DS and on PC, works great.
-Tried piggybacking another SD card slot (just so I didn’t have to take the other one off), same issue.
-Compared voltage drop readings from a working 2DS to the faulty one. All reads are very close except one, the 7th pin from the left, with the pins closest to you, which I believe is the clock pin (from a pinout of an SD card slot I looked at). Working unit had a voltage drop of .458 while the faulty one has a voltage drop of .768 (red probe on ground for both tests using the same ground pad).
Looking at the board, TP103, just next to the SD card slot connects to pin 7 of the slot. It also connects to the bottom left most pin in (the first pin in the row of three) of component DA3, which has D60 engraved in the case of the component. Its a 5-lead component (2 on the top, 3 on the bottom). One post I saw on another forum suggested it “appear to be TVS diodes in SOT-5 packages” though they were not able to confirm that.
I pulled DA3 from both my working board and then from the faulty board to measure the voltage drop on all of the pads DA3 was connected to. My working board measured the same voltage drop readings as before. The faulty board, however, had the bottom left pin of DA3 (the suspected clock pin) read OL. I assume I will need to look for the next component in the line after DA3 but I am at a bit of a loss as to what that is. I am going to try to beep this board out some to figure out what is next in line but if it goes to a BGA next, I probably won’t be able to find it.
Anyone happen to have an idea on this one?