Identify an I2C eeprom ? - Page 1
Forum section: electronics / projects

author: artag
author_rank: Super Contributor
timestamp: September 28, 2025, 08:14:54 pm
content: I have what appears to be an I2C eeprom marked A17 051 (or possibly D51 or 051). It's in a 6 pin SMD package and the host machine is talking to it in I2C. It's an ink level / anti copy device.Does anyone recognise that number ?Also, is there a forum somewhere for discussing hacking anti-copy devices or do the many clone manufacturers keep their knowledge secret ?

author: amyk
author_rank: Super Contributor
timestamp: September 28, 2025, 09:32:54 pm
content: Likely to be a custom marking, but what's the pinout and apparent capacity?There are some related threads here...https://www.eevblog.com/forum/projects/lexmark-toner-chip-ti046b1/https://www.eevblog.com/forum/reviews/dymo-550-thermal-printer-drm-hacking/

author: artag
author_rank: Super Contributor
timestamp: September 28, 2025, 10:42:22 pm
content: To be confirmed. I may have SDA/SCL swapped, and pin 2 may be connected to gnd as an address input as likely is pin 5I need to pull it apart again.(confirmed SDA on pin 1 and pin 2 not connected to gnd or V+)Code:_______SDA | o | SCLKn/c | | gndV |_______| gnd

author: HwAoRrDk
author_rank: Super Contributor
timestamp: September 29, 2025, 02:07:26 am
content: You might be looking at something custom.It seems that only Microchip make I2C EEPROMs in SOT23-6 package - 24xx or 34xx series - but none of the pin-outs of those match. All of those have the SDA & SCL pins on one side or the other (e.g. pins 1+3 or 4+6), not split between sides like you have.

author: artag
author_rank: Super Contributor
timestamp: September 29, 2025, 11:11:15 am
content: Could be. I need to investigate the protocol more - It's definitely I2C and at first glance it appeared to be memory but I may be wrong.I've built a pogo pin connection now to make it easier to probe.I thought all the chips were identical - they all have the same pcb and silkscreen - but on closer inspection I find another one has different markings, The one described is for the black cartridge but the Cyan is A17 022,. I haven't checked the others. Could be a date code though.I don't think it's SOT23-6. The legs are rather short for that. It's not quite LCC but close to that.

author: ftg
author_rank: Frequent Contributor
timestamp: September 29, 2025, 02:50:40 pm
content: That looks like DFN or QFN.No legs so definitely not SOT.Good pictures and mentioning what cartridge it is from might also help in potentially identifying it.

author: artag
author_rank: Super Contributor
timestamp: September 29, 2025, 02:58:21 pm
content: It's not completely legless, it has more than just a copper stripe on the side of / under the package. But it's very short.Cartridge is for a sawgrass sg500 sublimation printer.

author: gamalot
author_rank: Super Contributor
timestamp: September 29, 2025, 03:28:19 pm
content: This is a typical DFN-6 package, which likely features an exposed pad underneath.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 29, 2025, 03:41:33 pm
content: now it would be a matter of sniffing or reading what's there thru some scanning to find the chip adresssay take an arduino with wire librairies ??some hintshttps://learn.sparkfun.com/tutorials/reading-and-writing-serial-eeproms/all

author: wraper
author_rank: Unknown
timestamp: September 29, 2025, 03:51:53 pm
content: Unless it's some very old type of cartridge which it does not seem to be, it's not a simple EEPROM but rather some crypto authentication chip similar to one in the datasheet attached below.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 29, 2025, 05:39:07 pm
content: something about theses printershttps://www.reddit.com/r/Sublimation/comments/reflfp/if_youve_got_a_sawgrass_and_youre_using/https://www.reddit.com/r/Sublimation/comments/rm9vo0/sawgrass_sg500_33_firmware_ink_issue/

author: artag
author_rank: Super Contributor
timestamp: September 30, 2025, 03:22:46 pm
content: Quote from: coromonadalix on September 29, 2025, 05:39:07 pmYes, I've discovered this. If I'd researched properly instead of making a snap decision at an auction I probably wouldn't have bought it. In fact, though, many of the cloned ink cartridges now advertise 'new chip'. The problem was apparently solved a year or so ago. In the meantime Sawgrass have lost a lot of customers. Stupid greedy business decision.I'm curious as to how they phased them in. Surely they bhad to support the existing casrtridges in the channel ? Which would correspond to the 'old chip' in clones ? There's also a problem with the PC side : they have now replaced the 'print manager' with 'print utility' which wants me to change the firmware. I have VERY old firmware - 1.something, probably about 3 years old. So that will probably be fine with older cartridges.However I further hope to run it on linux using gutenprint icc software so I won't use the sawgrass print driver for longer than I need to.Finally, if it's a complete failure I didn't pay anywhere near list price. If I can't make it work I'll do a teardown for documentation and sell the bits as spare parts. Maybe try to put the Ricoh sofware on it (sawgrass are just a badge-engineering company).

author: artag
author_rank: Super Contributor
timestamp: September 30, 2025, 03:32:19 pm
content: Quote from: coromonadalix on September 29, 2025, 03:41:33 pmI'm seeing a lot of access to i2c address 51 in a format that suggests an eeprom. There seem to be extensive writes but that may be supportable for something as shortlived as an ink cartridge. Or it might be an FRAM - I did dsee a hint somewhere that they might use one. However if it uses a device as fancy as the one wraper mentions then it retains an eeprom-like access and many cloners were able to copy it..I do notice amongst the accesses to address a few short operations on address 7c. So it could well be a custom device.

author: artag
author_rank: Super Contributor
timestamp: September 30, 2025, 03:33:56 pm
content: Quote from: wraper on September 29, 2025, 03:51:53 pmThanks, an interesting read. It is actually quite old though, and the ID scheme has been cracked at least twice. So probably not that exotic.

author: wraper
author_rank: Unknown
timestamp: September 30, 2025, 05:55:29 pm
content: Quote from: artag on September 30, 2025, 03:33:56 pmIf it was just an EEPROM, it would be cracked once and last forever.