Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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Seagate ST4000DX001 Rom chip Identification ...

February 11th, 2024, 7:23

Hello all,

I have an EZP2023+ Usb programmer and am trying to backup the ROM/BIOS chip from the PCB of a Seagate ST4000DX001 4TB hard drive.

The EZP2023+ detects the chip as an EEPROM24 but cannot identify the actual chip itself.

When looking under the microscope the details on the chip as as follows:- 25S81 005 LUBH

Can anyone offer any assistance as to what this chipset is? Will I need to get a better USB programmer that can read a more comprehensive list/database of Bios/Rom chips?


Many thanks!

V. :D

Re: Seagate ST4000DX001 Rom chip Identification ...

February 11th, 2024, 20:45

https://ipv4.google.com/search?=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+25S81

I use "absolute maximum" to filter out spammy web sites.

LE25S81MC, Onsemi, serial flash memory, 8Mbit (1024K x 8), 1.65V - 1.95V, marking 25S81, SOP8J:

https://www.mouser.com/datasheet/2/308/on_semiconductor_onsms38180-1-1740660.pdf

Re: Seagate ST4000DX001 Rom chip Identification ...

February 12th, 2024, 2:40

https://ipv4.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+25S81

Re: Seagate ST4000DX001 Rom chip Identification ...

February 12th, 2024, 7:49

Hi fzabkar,

Thank you for the information. I will see if any of the relevant details on that datasheet will allow me to read the bios chip I have.

Pity that the USB programmer cannot identify the chip, and pity that the chip itself has sparse details stamped upon it too.

Interestingly, the EZP2023+ sees the chip as an EEPROM24. I would have thought that it would have been an EEPROM25 (as the chip says 25S81 on it).

Anyway, many thanks for the infformation.

V. :D

Re: Seagate ST4000DX001 Rom chip Identification ...

February 12th, 2024, 9:43

From datasheet:
The LE25S81MC is a SPI bus flash memory device with a 8M bit (1024K × 8-bit) configuration.
Read/write operations enabled by single 1.8V power supply : 1.65 to 1.95V supply voltage range.
Maximum supply voltage −0.5 to +2.4 V!
If magical smoke has not yet left the chip, we need an adapter for 1.8V...
https://www.aliexpress.com/w/wholesale-1-8v-adapter-programmer.html?spm=a2g0o.productlist.auto_suggest.1.4d3dmuzlmuzlyY

Re: Seagate ST4000DX001 Rom chip Identification ...

February 13th, 2024, 6:09

Thank you SWM.

Much appreciated.

V. :D
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