Damaged Fin after power supply failure


We had an accidental short between the positive and negative outputs of our power supply that was powering one of our Fins. After replacing the power supply we could not get the Fin to boot. When booting the Fin in MSD mode it enumerates as a 32.1 MB block storage device rather than the expected 8 GB. My best guess is the MMC was interrupted during a sensitive operation. Has anyone run into this before, and have you found a way to recover from this state?

[349024.872401] usb 3-2.7.7: new high-speed USB device number 30 using xhci_hcd
[349024.973035] usb 3-2.7.7: New USB device found, idVendor=0a5c, idProduct=0001
[349024.973037] usb 3-2.7.7: New USB device strings: Mfr=2, Product=1, SerialNumber=3
[349024.973038] usb 3-2.7.7: Product: Compute Module
[349024.973039] usb 3-2.7.7: Manufacturer: Raspberry Pi
[349024.973040] usb 3-2.7.7: SerialNumber: 257c76f6
[349024.973568] usb-storage 3-2.7.7:1.0: USB Mass Storage device detected
[349024.973755] scsi host6: usb-storage 3-2.7.7:1.0
[349026.004773] scsi 6:0:0:0: Direct-Access     RPi-MSD- 0001                  PQ: 0 ANSI: 2
[349026.005055] sd 6:0:0:0: Attached scsi generic sg3 type 0
[349026.005612] sd 6:0:0:0: [sdc] 62688 512-byte logical blocks: (32.1 MB/30.6 MiB)
[349026.005753] sd 6:0:0:0: [sdc] Write Protect is off
[349026.005754] sd 6:0:0:0: [sdc] Mode Sense: 0f 00 00 00
[349026.005878] sd 6:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[349026.015551] sd 6:0:0:0: [sdc] Attached SCSI removable disk


Hello @aferm, we have seen a case where after power issues the eMMC reported 32MB storage. Unfortunately, we haven’t found a way to recover it to the original size. We are currently talking to the manufacturer to see if there is a way to get the devices back to the original state. I will keep this post updated when I have more news.
What type of power supply were you using when the short happened?




We were using a 12V battery backed solar system. The short was caused by an improperly insulated battery terminal coming into contact with our grounded metal enclosure.