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Tektronix 2430a ram chip question

Discussion in 'Troubleshooting and Repair' started by dewey wyatt, Apr 7, 2018.

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  1. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    my 2340a tek scope has a memory error, battery low it uses the dallas chip with battery in the chip. I ordered two new ram chips and the sockets but I have no chip reader writer to copy the memory from the old to the new. question is what kind of reader writer do I need to do a 28 pin dip? will the ebay jobs work ok or do I need better? thanks for the help.
     
  2. Bluejets

    Bluejets

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    Oct 5, 2014
    Never seen a battery in a chip before.
     
  3. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    well, check this out two batteries in it they switch and they lasted since 1989.
    The DS1230AB-70IND+ is a 256KB non-volatile SRAM in 28 pin EDIP package. It is a 262,144 bit, fully static, non-volatile SRAM organized as 32,768 words by 8 bits. The NV SRAM has a self contained lithium energy source and control circuitry which constantly monitors VCC for an out of tolerance condition. When such a condition occurs, the lithium energy source is automatically switched on and the write protection is unconditionally enabled to prevent data corruption. This device can be used in place of existing 32K x 8 static RAMs directly conforming to the popular bytewide 28 pin DIP package. The DIP device matches the pin-out of 28256 EEPROMs allowing direct substitution while enhancing performance. This device is low profile module package are specifically designed for surface mount applications. There is no limit on the number of write cycles that can be executed and additional support circuitry is not required for microprocessor interfacing.
    • Supply voltage range from 4.75V to 5.25V
    • Operating temperature range from -40°C to 85°C
    • Replaces 32K x 8 volatile static RAM, EEPROM or flash memory
    • Unlimited write cycles
    • Low power CMOS
    • Read and write access time is 70ns
    • Lithium energy source is disconnected to retain freshness until power is applied for the first time
    these are what is in it now and I will replace both with these and sockets when they come in if I can figure out what I need to reprogram the chip
     
  4. Bluejets

    Bluejets

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    Oct 5, 2014
    Fair enough but if there is a memory error showing, would transferring existing memory into a new device still end up with the same error.
    Or is it just signalling that the battery is low?
    If the latter, then leaving the unit switched on and replacing the power module (if fitted) should be all that is required.
    Might be time for a new unit.
     
    Last edited: Apr 8, 2018
  5. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    it only signals low voltage, when it goes dead its is a paperweight. reason I am looking for a reader to try and save it. whe I bought it I said it would be the last scope I bought and it will be. if it ends up a paperweight so be it
     
  6. Bluejets

    Bluejets

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    Oct 5, 2014
    All may not be lost.
    I found this service manual (link below) and according to it, (in the service calibration section) replacing the NVSRAM involves doing a "cold start".
    So from that I deduce that you may not need any external reader/writer.
    Anyhow, see what you think.
    I believe I have the correct manual.

    I would be inclined though to read the entire section and get the details straight before attempting any change or whatever.

    https://www.tek.com/manual/2430-service-manual

    Google is a great place to start................................:cool::)
     
  7. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    yes on the 2430, mine is the 2430a it was a later model when they switched memory to self contained. less parts more profit same scope specs. there has to be a way without having to send it back for factory cal.
     
  8. Bluejets

    Bluejets

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    Oct 5, 2014
  9. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    I got the service manual when I bought the scope, the ones on the net are slightly different than the one i have. mine was thru the usaf. I will scrap it before I go thru recalibrating it.
     
  10. Bluejets

    Bluejets

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    Oct 5, 2014
    You provided a model number which was all I could go by so if yours is different again then perhaps you could have stated that a bit earlier on.
    Would have saved some unnecessary searching and deciphering.
     
  11. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    all I asked was which programmer I needed. there is no option in the manual for this
     
  12. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Neither have i.
     
  13. Bluejets

    Bluejets

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    Oct 5, 2014
    You might be overreacting as to the importance of this battery backup chip ( if it does indeed even exist on your model)
    I saw reference to it in the first manual but not inthe "a" model. It said expected lifespan was 3 years. Now I cannot imagine a company like this releasing a test meter that would "brick itself" after an expected 3 years( well, Apple maybe)
    Manual also says it is for storing " front panel settings".
    As I have no intention of reading over 400 pages, I cannot really say if there is other data but perhaps a call to the makers may shed extra light.
    Manual quotes the chip you refer to is shipped in an off state to preserve shelf life and only kicks in after first powerup. To me that infers the cold boot is merely amachine boot up sequence perhaps by placement of a jumper or similar.
     
  14. JWHassler

    JWHassler

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    Dec 22, 2014
    Have a read of this
     
  15. dewey wyatt

    dewey wyatt

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    Apr 7, 2018
    thanks jw, I had already found and read the paper. found an other which led to replacing the sram with fram namely fm18w08 which I am gonna try later as soon as the parts arrive. I have the new dallas ds1230ab 2015 date code and waiting on the reader writer to come tomorrow. bluejets you don't need to read the manual
    and battery life in the 2430a was 10 yrs. it outlived that by 11 yrs. if the battery goes dead then calibration is lost which requires complete calibration, latter is what I want to avoid .the 2430 was a completely different animal as far as battery goes just replace a button battery. these are inside the chip itself, not external and there was no provision to hold the data for battery changes.
     
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