gerald.wert Posted February 17, 2017 Report Share Posted February 17, 2017 (edited) I had been getting the following error from the terminal when trying to access the sdcard on my STM32F4 core: [[35355.231] SD Card Informations [35355.231] ==================== [35355.231] ERROR: Reading CID failed with status -256! [35355.231] ERROR: Reading CSD failed with status -256! [35355.231] [35355.231] Reading Root Directory [35355.231] ====================== [35355.231] SD Card: not connected [35355.232] Failed to open root directory - error status: 12 [35355.232] [35355.232] Checking SD Card at application layer [35355.232] ===================================== [35355.232] Current session: /SESSIONS/DEF_V4L [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_B1.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_B2.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_B3.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_B4.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_M.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_S.V4: doesn't exist [35355.232] File /SESSIONS/DEF_V4L/MBSEQ_G.V4: doesn't exist [35355.233] File /SESSIONS/DEF_V4L/MBSEQ_BM.V4: doesn't exist [35355.233] File /SESSIONS/DEF_V4L/MBSEQ_C.V4: doesn't exist [35355.233] File /MBSEQ_C.V4: doesn't exist [35355.233] File /MBSEQ_BM.V4: doesn't exist [35355.233] File /MBSEQ_HW.V4L: doesn't exist or hasn't been re-loaded [35355.233] done. I checked around on the forum and had seen a lot of people having issues with wiring , the card slots and the format on the cards. Mine turned out to be bridged pins under the LQFP100 on the STM32F4 board. Here are the relevant pins if you are having issues as well: LQFP100 P1 PA5 30 15 PA6 31 18 PA7 32 17 PB2 37 24 Here is J16 looking down on it _________ | VS --- VS | -------> to ground | VD --- VD | -------> 3.3V (the STM32 actually only puts out about 3 volts) SI SO | SI ----> PA6 SO ---> PA7 | SC --- SC | --------> PA5 | RC2 RC1 | RC2 --> PD11 RC1-->PB2 (RC1 goes to the onboard SDCard reader or a card on J16 if there is no card in the reader ---------------- RC2 is for a second Card and not needed for most testing. I figured the board was already messed up so I decided to try fixing it. Those pins are super small and hard to work with. There was a dead short between PA6 and PA7 I was able to lift pin PA6 and cut the trace with a razor blade and solder a jumper directly from the pin to PA6. I would think this error would more likely happen from a solder bridge elsewhere and the STM should pass QC. The pins are pretty easy to test as they go straight to the ARM Processor. The also nicely went in order down the side. PA5 was pin 5 on that side of the chip. The white silkscreen on the board makes it a lot easier to keep track of the pins they are marked every 5 pins. The jumper might look a like it is crossing things in the photo but the pin is bent up and out so there is plenty of clearance. I tried solder wik, reflowing the pins, my hot air rework iron, cleaning between the shorted pins with a razor blade, and even removed the header pins hoping the short was there before lifting the pin but nothing else worked for me. Edited February 17, 2017 by gerald.wert Quote Link to comment Share on other sites More sharing options...
latigid on Posted February 18, 2017 Report Share Posted February 18, 2017 Good sleuthing! Thanks for the write-up. I hope they'll send a replacement. When doing bodge repairs like this you can consider using thin enamelled wire, i.e. "Verowire" or even that used to wind transformers/coils. Quote Link to comment Share on other sites More sharing options...
gerald.wert Posted March 8, 2017 Author Report Share Posted March 8, 2017 Verowire would be a lot better. I was going to use some wire wrap or the verowire but could not find where either the rolls had gotten off to. The ribbon wire worked but is just so big compared to the pin. I debated some solid telephone wire but decided the advantage to the ribbon wire is that it is stranded so hopefully will put less strain on the pin. ST said that the processor on the board does not match production to what they install on the discovery boards and that I would have to go back to the person I bought it from. I looked it up and I actually had bought it on amazon listed as new with a gift card. Basically just stuck with it now. It was a bit disappointing ST did not stand behind their product but also understand their point of it being tampered with. Glad I went ahead and fixed it instead of waiting a week or more on their refusal of support. Quote Link to comment Share on other sites More sharing options...
latigid on Posted March 8, 2017 Report Share Posted March 8, 2017 Yeah, I think some others also had trouble with pirate DISCO boards. But if it works, there's no problem! Quote Link to comment Share on other sites More sharing options...
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