Don't Miss

What No One Tells You About Data Recovery from Broken EEprom IC

By on January 19, 2016








Hi folks!

I got a couple of days ago a phone call from a company about a sophisticated job, as I told, it is really sophisticated. They ask me to make a data recovery from a broken EEprom IC. I decide to take the job and let’s see what about it is.

So, the company has an EEprom which was gone really bad but this is the only one on the earth with the specific data in it which they must have. If the data would be unrecoverable then, they lost a very expensive machine, maybe somebody lost his job. I was thinking, hu-huuu what type of machine could that be? Maybe a space rocket?

Ok, let’s start:


The EEprom type is an ST93CS56 which means it is a write protected EEprom, not a usually one. The equivalent all days EEprom is the ST93C56 which have no memory protection function. This special EEprom was in most of case fabricated for special customer’s like the military, special medical labs industry, car industry etc…

The worst problem was with this EEprom does you can’t write data into with a usually EEprom programmer, but you can some time read out the data. Some technicians who repaired that specific machine broke one leg from the EEprom IC. Now it is no more connectable to the original PCB or to any other device for backup.

Until I checked the other legs I saw there was another leg broken. So, now I deal with an EEprom who have two legs broken. The first thing what I have to do is somehow connect to the broken pin place a wire. That I achieved when I took a small round rasp and gently removed slice by slice the package of the IC. After 40min of gently filing I got to the leftover pin which was broken deep in the body of the IC. Then I soldered a wire to the cooper plate, so I got a connection to the internal world of the EEprom.  Here is how that looks like:



And here is how the finished soldering looks like:



And another picture where I soldered all the legs to my home made smd to DIL adapter.

eeprom data recovery

After this I fired up my famous EEprom reader/writer the SEEPROG and try to read out the content. It worked, the data was stored in the buffer of the EEprom programmer and I could save them to my hard drive. I sent the data back to the company who offered me to do this job, and I have asked them to send me a feedback to see if the data are good or corrupt.

Few days later I got a nice call from the company saying the data recovering was successful and the machine was working again. So, this is a technique what I use whenever an IC got some pin damaged and the data should be read out for some reason. I have tried this on lot’s of EEproms and CPU-s too.

In most of the case I could read the data and then reload it to another same IC and fix the problem on that tool, machine, equipment whatever.  I hope you enjoy this tutorial and will save lot of repair time.




This article was prepared for you by Christian Robert Adzic from Novi Knezevac-Serbia.

Please give a support by clicking  on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

P.S-  If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!

Note: You can check his previous post in the below link:




  1. David Maltz

    January 19, 2016 at 9:30 am

    You sure earned your money on that one. Great repair.

  2. beh

    January 19, 2016 at 10:18 am

    Well done CHRIS

  3. Mark

    January 19, 2016 at 10:47 am

    Hey Christian,
    I am impressed with the depth of your programming skills. This is one area that I don't know much about, but would like to learn. I have had a brief look at some universal reader/writers. It appears the one you mentioned is no longer available and has been replaced by the MEMprog2. What are your thoughts on the MiniPro tl866? It seems to be a little closer to my price range.
    Can you recommend any web sites, videos or articles that would be useful to learn about programming, especially EPROM's on TVs etc.? Where do you get the original programs to write to new chips?
    Keep up with the informative articles!

    • Chris

      January 24, 2016 at 8:20 am

      Thanks for supporting my article.
      I have no clue right now about web's or video's about eeprom programming but I can say, the first step by me is to look into the data sheet of the desired eeprom. There should be written the most stuff.
      You have to own quality tools to work with eeproms. I think the most of the stuff is done by the eeprom programmer. So, you make one for you or you buy one.
      When you have a good eeprom programmer, then you can concentrate on the repair stuff. Otherwise you are in trouble.
      If I see an eeprom in a device what I'm repairing then I read out the content and save it to my PC. Maybe I can reuse the content in some other situation. This is my most valuable task when I recognize an eeprom.
      I also get the content from the internet, from forums from guy who have a device in their service room and can read out for me. Always ask if you need something, otherwise nobody knows does you need help.
      If this dos not work then I check on some electronic junk yard for a device and then hopefully I find what I need.
      This is some of my steps of my researches...
      If I can hep you please feel free to ask me.
      My best regards.

    • Chris

      January 24, 2016 at 8:56 am

      I checked this eeprom programmer what about you asked, the MiniPro tl866. I think it is a nice programmer. It is worth the money.
      The software is nice and not hard for understanding and the whole product is clear and nice.
      So, buy one and introduce it. 🙂

      • Mark

        February 24, 2016 at 5:57 am

        Hey Chris,

        Thanks for your advice. I might look into getting one of those units.

  4. Charles Borromeo

    January 19, 2016 at 11:55 am

    Hi Mr. Christian, Nice job and well explained, Thanks for the article.

    Charles Borromeo.
    Burma (Myanmar)

  5. Robert Calk

    January 19, 2016 at 12:00 pm

    Nice job, Chris! Thanks for sharing your work with us.

  6. skwong

    January 19, 2016 at 12:09 pm

    You have done a great job with ease in a professional way. It may look crude but I guess it is the best solution to recover the data or else it can be a nightmare. I have done a similar job connecting a wire to one of the cpu ic lead which is broken.

  7. Rajeshputta

    January 19, 2016 at 1:02 pm

    It is very great job that you done.
    I have a request here.
    That I am also facing same kind of problem, the EEPROM program not functioning, if possible to give service to us?
    Let me know, I will share the details.

    Waiting for your reply.

    Thanking you

    • Chris

      January 24, 2016 at 8:23 am

      Thanks for supporting my article.
      What you mean under "the EEPROM program not functioning" how you checked that?
      Pleas let me know about your problem?

      My best regards.

  8. Parasuraman S

    January 19, 2016 at 1:19 pm

    Vow! Something unimaginable by me! Hat's off to you for your high skill and proficiency! Learnt something new today from you! Many thanks, and keep it up!

  9. Gopal Sharma

    January 19, 2016 at 1:46 pm

    Thanks for sharing, Its nice technique to recover data.

  10. Aref

    January 19, 2016 at 2:08 pm


  11. Yogesh Panchal

    January 19, 2016 at 2:15 pm

    Good trick! to get the data back .Thanks for sharing your experience.

  12. zed

    January 19, 2016 at 4:01 pm

    nice info on how to retrieve eeprom data sir Chris

  13. Albert Hoekman, Holland

    January 19, 2016 at 6:00 pm

    Hello Christian, nice job! Thanks for sharing this, keep on going.

  14. Paris Azis

    January 19, 2016 at 6:20 pm

    Hey Christian

    Excellent job! Thanks for sharing it.

  15. AKASH

    January 19, 2016 at 6:24 pm

    WOW! great work i was always wondering how to recover data from such IC's

  16. Pacoska

    January 19, 2016 at 6:37 pm

    Very interesting information.Thanks a lot.These days I have to read an old PIC controller PIC16F77-I/P but I cannot due it's protected with the fuse CP (Code protect). Do you know any technique to access to the programm?

    • Chris

      January 24, 2016 at 8:25 am

      Thanks for supporting my article.
      When I back in my lab where I actually work I will check about your problem and try to figure out a way how to read the content from that kind of device.

      My best regards.

      • Chris

        January 24, 2016 at 8:37 am

        Here is some starting point article what maybe you like to know.
        This area is from my time when I learned about using this stuff and how to get access to some other stuff.

        My best regards.

  17. mohamed yahia

    January 19, 2016 at 6:39 pm

    Good job Mr Christian, and many thanks for sharing new information technique.

  18. Albert van Bemmelen

    January 19, 2016 at 7:04 pm

    Hi Chris, you are a real Pro with Serial Eeproms! The Firm who called you however must really be the stupidest Firm on Earth. Seeing how they not only destroyed the only programmed serial chip they had but also their life's work with it!! I wonder where they placed the original file to program the Serial EEprom with in the first place? Since it didn't go in the little 8 pins chip without programming it from a source file first!

    • Dennis Breda

      January 20, 2016 at 12:54 am

      We all can mess up at some time in our career. Thanks for people like Christian who can take up the challenge and help.

  19. Anouar

    January 19, 2016 at 8:23 pm

    Great repair ,good job

  20. Gerald Millward

    January 20, 2016 at 8:05 am

    This is proper repair work. Getting data off an eeprom is one thing, but to be aware of the possibility of shaving off enough plastic cladding to get at a connection point is very much another. A magic blend of theory and practice. Great work Christian - a lesson to us all.

  21. saffi

    January 21, 2016 at 4:06 am

    it's beautiful, thank you very much.

  22. Gary Gemmell

    August 10, 2016 at 9:36 am

    Truly impressive work.
    Now thats real repair work!

  23. Mike

    December 2, 2017 at 1:15 am

    Greetings! I just read your article about how you managed to solder the broken pins of an IC and recover the company data. Very impressive job indeed! I am an electrical engineer student from Portugal and I am really thrilled with these type of projects. If you had a solution for a problem I would be really appreciated. In short words, I have an lcd c.board with two IC´s in which, one of them burnt (tiny burn hole, Vcc & SDA shorted to GND). With a little of research and only knowing from the IC information (L02W), came up to realise I am probably working with a 2kb eeprom ic ( ( Identical to mine but not exactly it. Mine is a mini-sop8. I thought of two solution, try to read & copy the good ic data using the method you used (converting sop8 to DIL adapter), at my university, still not knowing if they have identical data OR, try to recover the lost data from the burnt IC and write it on a new IC. What would you sugest me to do with your experience? Thank you for your time! Have a good day,

  24. Ihtasham

    March 26, 2018 at 12:16 am

    I am from Pakistan and I intend to send one of my eprom toi you for data recovery. Can you do that?
    Our paper machine is stopped due to this problem.

    • Christian Robert Adzic

      July 20, 2018 at 9:11 am

      Sorry because I'm late.
      Yes I can give a try.
      No problem.


Leave a Reply

Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.