Two genuine Sandisk Extreme Pro cards with same S/N?

[fzabkar]

According to Sandisk Support Live Chat two Sandisk Extreme Pro Card can have the same serial number:

https://old.reddit.com/r/datarecovery/comments/1n7k0lg/according_to_sandisk_support_live_chat_two/

https://forums.sandisk.com/t/both-cards-have-same-serial-number/417497

https://forums.sandisk.com/t/same-serial-number-on-both-extreme-pro-cards/417498/2

Isn't this absurd?

[HaQue]

It is, but Sandisk participate strongly in flash specifications and then totally disregard and standards whenever they feel like it. Documentation is often incomplete, wrong or wildly outdated. Thier love of using model names for ever changing internals is another source of confusion. I have a Sandisk Cruzer is about as informative is saying I have a Camry.

[fzabkar]

I don't think you understand me. I'm saying that two cards cannot have the same serial number, despite what SanDisk's TS people are claiming. At the very least, it would create a logistical problem if two people with the same serial number were to claim a warranty replacement.

In fact, I uncovered several anomalies when researching these serial numbers.

https://support-en.sandisk.com/app/answers/detailweb/a_id/53002

Code:

CCYYDDDXXXXXL (SanDisk web site)

CC = product code ??
YY = (20)YY - year
DDD = day
XXXXX = unique s/n
L = location of manufacture ?

Code:

CCYYDDDXXXXXL (SanDisk web site)

BL1229822505G (outsidetheshot.com)
BM1334150100G (storagereview.com)
BN1615950860G (eBay)
BP1832551766G (cameramemoryspeed.com, review)
BP2005153036G (shashinki.com, vendor)
BP2031453594Z (bulkmemorycards.com)
BP2035053593Y (bulkmemorycards.com)

BM22122001721Z (techgearlab.com)
BN22295001718G (uzum.uz, vendor)
BN25078001721Z (SanDisk user)
  YYDDD^^^^^^L

This is a summary of the cards in chronological order. Something is different about the last three cards. Firstly, they have an extra digit in the s/n. Secondly, they seem to be out of order. That is, the BN/BM prefix should be in alphabetical order, just like the other BN/BM cards. Thirdly, the serial numbers are either identical or very similar (eg 001721Z), apart from the date.

This blog purports to teach the reader about SanDisk numbers, but it would appear that their samples are probably fakes.

Model Number vs Serial Number, What's the difference?
https://bulkmemorycards.com/model-number-serial-number/

Code:

BP2031453594Z (bulkmemorycards.com)
BP2035053593Y (bulkmemorycards.com)
  YYDDD^^^^^L

The article would suggest that these two cards may have been procured at the same time, yet their manufacture dates differ by 36 days, although their serial numbers are consecutive.

[fzabkar]

After more research, I believe that the number of the SD card is a "date code" rather than a serial number. If so, then SanDisk's technical article has numerous errors, and this number need not be unique.

Where to Find SanDisk Model, Part Number, Date Code, for Product Registration or Warranty Replacement:
https://support-en.sandisk.com/app/answers/detailweb/a_id/53002

The article states that "Serial Numbers are unique" and "Date Codes are not unique".

Code:

CFexpress Card                   - Serial Number on the product - YYWWLLMXXXXX
CompactFlash Card                - Serial Number on the product - YWWDMTLLLXXX
microSD and microSD Express Card - Date Code on the product     - YWWDMTLLLXXX + CC
SD and SD Express Card           - Serial Number on the product - CCYYDDDXXXXXL
USB Flash Drives                 - Date Code on the product

Notice that the CompactFlash and microSD cards have the same number format, but different description. Something is wrong here.

I also noticed that USB flash drives appear to have a numbering format of CCYYMMXXXXXL.

Code:

SanDisk Ultra USB flash drive

BL121024800B   China         https://ounapuu.ee/posts/2023/02/15/shrinkflation/media/image-2.jpg
BL131024746B   China         https://www.rflashdata.com/wp-content/uploads/2015/08/Sandisk-Ultra-USB-3.0.jpg
BN140824800B   China         https://img.danawa.com/prod_img/500000/831/196/img/2196831_4.jpg?_v=20181120134925
BM151125257B   China         https://ae01.alicdn.com/kf/S1ef3815c1f57410aa7e762ea4c511edcP.jpg
BL171125745W   Malaysia      https://i.ebayimg.com/images/g/F88AAOSwk~Rm~A1v/s-l1600.webp
BM171226162B   China         https://i.ebayimg.com/images/g/2UAAAOSwD4RctZj4/s-l1600.webp
BP20120017644  Malaysia      https://archive.goughlui.com/wp-content/uploads/2021/10/2021101309479736.jpg
BP2107002263W  Malaysia      https://imgur.com/LmbhQ25
BP2108004404W  Malaysia      https://imgur.com/LmbhQ25
BR220258047W   Malaysia      https://i5-richmedia.walmartimages.com/asr-rm/f247c89b-ca69-49e2-bae0-e86330ec52af_360_merchant_manual_12.jpg
BN22050031084  Malaysia      https://sg-test-11.slatic.net/other/roc/a64b2a0622494326cd6322895f7893d4.jpg
BL2210001378W  Malaysia      https://ounapuu.ee/posts/2023/02/15/shrinkflation/media/image-2.jpg
BQ2304005965W  Malaysia      https://ugc-user-content.pccomponentes.com/IMG_658064cd8525c_20231218152709545370.jpg
BN2311001183Z  China 3-pack  https://cdn.idealo.com/folder/Product/201934/6/201934693/s1_produktbild_max_8/sandisk-ultra-usb-3-0-64gb-3-pack.jpg

I found this official SanDisk document that describes the marking spec of an AirCruzer wireless flash drive:

https://fccid.io/R4V-SDWS2/Label/lable-2031553.pdf

Code:

CCYYMMXXXXXL

CC    = Memory Capacity
YY    = Year: 12=2012
MM    = Work Month: 01-12
XXXXX = Technology Code (5 digits starting from 54-98-XXXXX)
L     = Subcontractor Code

The mysterious XXXXX digits represent a "Technology Code", so they are probably not unique.

Other SanDisk marking specs:

iXpand™ Memory Case:
https://fcc.report/FCC-ID/R4VSDIPB/2964288.pdf

Ixpand Wireless Charger 15W:
https://fccid.io/R4V-SDHZB0N/Label/ID-label-and-location-4867659.pdf

I also found this "Time Shift Buffer Hardware Specification":

https://account.cablelabs.com/server/alfresco/b5172002-e439-4eb4-9d67-2e5054b1d3bc

The SD card looks very much like SanDisk's cards. In this case the mysterious XXXXX digits are the "Last 5 digits from Bill of Materials".

Code:

6.1.3  SD Card Labeling

Each SD Card MUST have the following labeling on the bottom of the card etched in during manufacturing:

• Card Capacity Code (CC).  See Table 4 for code mapping to capacity.
• YYDDD to indicate the year and day in that year when the card was manufactured
• Last 5 digits from Bill of Materials
• Single character Manufacturing site indicator
• Memory lot identifier

Table 4 - Capacity Code Mapping

Capacity Code    Size
-------------   ------
BH               4 GB
BI               8 GB
BL              16 GB
BM              32 GB
BN              64 GB
BP             128 GB