Wow, these look like great tools you have written to really drill down to what the issue might be. Here is the output of one of the cards using just the default format that comes on them from the factory. I'm formatting another one with SDFormatter v3.1 and will run the tests again. It is interesting that these come labeled as 1G cards, but all indications are that they are 2G cards. Wondering if they are the 2G seconds that were rejected and reformatted as 1G.
::::::::::: SdInfo :::::::::::::::::::::
SdFat version: 20120719
type any character to start
init time: 5 ms
Card type: SD2
Manufacturer ID: 0X0
OEM ID:
Product: APPSD
Version: 3.0
Serial number: 2290649224
Manufacturing date: 10/2010
cardSize: 4014080 (512 byte blocks)
flashEraseSize: 128 blocks
eraseSingleBlock: true
SD Partition Table
part,boot,type,start,length
1,0X0,0X6,245,4013835
2,0X0,0X0,0,0
3,0X0,0X0,0,0
4,0X0,0X0,0,0
Volume is FAT16
blocksPerCluster: 32
clusterCount: 62679
freeClusters: 62643
fatStartBlock: 251
fatCount: 2
blocksPerFat: 245
rootDirStart: 741
dataStartBlock: 773
Data area is not aligned on flash erase boundaries!
Download and use formatter from www.sdcard.org/consumer!
:::::::: QuickStart:::::::::
SD chip select is the key hardware option.
Common values are:
Arduino Ethernet shield, pin 4
Sparkfun SD shield, pin 8
Adafruit SD shields and modules, pin 10
Enter the chip select pin number: 20
Card successfully initialized.
Card size: 2055 MB (MB = 1,000,000 bytes)
Volume is FAT16, Cluster size (bytes): 16384
Files found (name date time size):
PWMGR 2000-01-01 01:00:00 0
TEST.TXT 2000-01-01 01:00:00 0
This card should be reformatted for best performance.
Use a cluster size of 32 KB for cards larger than 1 GB.
Only cards larger than 2 GB should be formatted FAT32.
Try reformatting the card. For best results use
the SdFormatter sketch in SdFat/examples or download
and use SDFormatter from www.sdcard.org/consumer.
Restarting
:::::::::::: SdFormatter::::::::::::::::
Enter the chip select pin number: This sketch can erase and/or format SD/SDHC cards.
Erase uses the card's fast flash erase command.
Flash erase sets all data to 0X00 for most cards
and 0XFF for a few vendor's cards.
Cards larger than 2 GB will be formatted FAT32 and
smaller cards will be formatted FAT16.
Warning, all data on the card will be erased.
Enter 'Y' to continue: Y
Options are:
E - erase the card and skip formatting.
F - erase and then format the card. (recommended)
Q - quick format the card without erase.
Enter option: F
Card Size: 1960 MB, (MB = 1,048,576 bytes)
Erasing
................
All data set to 0x00
Erase done
Formatting
Blocks/Cluster: 64
FAT16
error: write MBR
SD error: 13,b
::::::::::::::::: Bench ::::::::::::::::::::::::
SdFat version: 20120719
type any character to start
Free RAM: 7301
Type is FAT16
error: open failed
SD errorCode: 0X13