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Testing NTE 2107 memory chip

Discussion in 'Electronic Components' started by Nick, Mar 3, 2007.

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  1. Nick

    Nick Guest

    Does anyone have a way of testing an old memory chip? I have a whole bunch
    of these out of an old Allen Bradley control cabinet. Some of them are
    marked P 2107 C-2. They are also described as IC-MOS 4K DRAM Chip. There
    are 22 pin IC package and I have hundreds of them that need to be tested. I
    have a BK 575 tester but it won't do the job and BK does not have any
    updates.

    Is there another chip out there in a different package but with the same
    type of pinouts where I can adapt it to the different chip that possibly the
    BK 575 can test.

    A bread-boarded test circuit would be nice also.

    Any help would be appreciated.

    Thanks,
    Nick
     
  2. Why do you want to test them? I'd be more likely to replace old DRAM with
    SRAM these days - much cheaper.
     
  3. Eeyore

    Eeyore Guest

    What on earth for ? Are you planning to re-use them somehow ?

    Graham
     
  4. Werty

    Werty Guest

    DRAM is so low on both Operating

    power and refresh m they call it PSRAM .

    It can refresh at about .0001 amp .

    I have 10 Nintendo DS Lite game-boxes

    im hacking . They are the lowest cost

    method , i have to get PSRAM .

    A 100 MB HDD is easily hooked to

    the slot-2 of DS Lite .

    I also have GP2X , HDD is easy , cause

    of USB host .
     
  5. Nick

    Nick Guest

    The idea is to repair the entire memory card and return it to service. There
    are 4 of these cards with about 30 of these memory chips on each one.
     
  6. You might have to build a tester, perhaps one just for these cards.
     
  7. Nick

    Nick Guest

     
  8. Nick

    Nick Guest

    I'd be glad to build a tester for this chip - would solve a real time
    waster. Now what I do is put a half dozen new chips on the board and see if
    the exec program for the machine will load. Then I do the Cristmas tree
    light thing untill I get the bad chips in my hand.

    Nick
     
  9. ISTR that PopTronics and or Radio Electronics published similar testers back
    when these were useful. Try a big city library if you can.
     
  10. Franc Zabkar

    Franc Zabkar Guest

    Does the board have a CPU (eg Z80) with a discrete PROM/EPROM? If so,
    how hard would it be to program a debug monitor or memory tester into
    your own ROM?

    - Franc Zabkar
     
  11. Nick

    Nick Guest

    The board is about 16" square with edge connectors along 1 side and it
    plugs into a backpane with a bunch of other cards. There is no real CPU or
    such as these are 1980 CNC controls. There are 34 of these 2107 chips in
    sockets on each card and they need to be pulled and checked. The easiest way
    would be a sister card adapted to my BK 575 IC tester.
    There are no EPROM's on these cards, so something else would have to be
    done.
     
  12. One way to check if a DRAM is working is to simply jam a second
    Known-to-be-good DRAM on top of the suspect one. This often works!

    Otherwise there are testers out there on eBay - RAMCHECK, BUGTRAP, and
    others made test units that would handle these.

    John :-#)#
    --
    (Please post followups or tech enquires to the newsgroup) John's
    Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
    (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
    www.flippers.com "Old pinballers never die, they
    just flip out."
     
  13. Oh, wait, is the 2107 an 18 pin with triple supply? Then there are not
    very many test fixtures for it...

    John :-#(#
    --
    (Please post followups or tech enquires to the newsgroup) John's
    Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
    (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
    www.flippers.com "Old pinballers never die, they
    just flip out."
     
  14. Nick

    Nick Guest

  15. moby

    moby Guest

    Buy this unit on Ebay
    http://cgi.ebay.com/Eventide-H-910-...0QQihZ005QQcategoryZ23790QQrdZ1QQcmdZViewItem
    Take the lid off it and you'll see a row of DRAMs just like the ones
    you want to test, they are socketed.
    The Right hand one is the most significant bit
    Set the harmoniser up as a simple digital delay
    Feed a signal generator at, say, 1khz, in the input and monitor the
    output on an amp and speaker.
    Go through your pile of dram chips one at a time, substituting them in
    the MSB socket, turning off while doing the swaps.
    Discard the chips that turn the sound to crap.
    If you want an easy life, plug a 22pin 0.4" zif socket in the MSB
    socket.
    Sell the Eventide on Ebay
    M
    M
     
  16. Nice. More fun than a dedicated tester (which might cost nearly as much if
    it's hard to get), and as the Harmoniser is well-liked by many, is
    guaranteed to resell, and for a profit if you get some nice big photos and
    a good description. Unless you damage the Harmoniser, it's unlikely that
    you could lose money this way, and you might like it enough to keep it and
    use it.
     
  17. John Hermann

    John Hermann Guest

    Buy this unit on Ebay
    http://cgi.ebay.com/Eventide-H-910-...0QQihZ005QQcategoryZ23790QQrdZ1QQcmdZViewItem
    Take the lid off it and you'll see a row of DRAMs just like the ones
    you want to test, they are socketed.
    The Right hand one is the most significant bit
    Set the harmoniser up as a simple digital delay
    Feed a signal generator at, say, 1khz, in the input and monitor the
    output on an amp and speaker.
    Go through your pile of dram chips one at a time, substituting them in
    the MSB socket, turning off while doing the swaps.
    Discard the chips that turn the sound to crap.
    If you want an easy life, plug a 22pin 0.4" zif socket in the MSB
    socket.
    Sell the Eventide on Ebay



    The old Space Invaders video game used the same DRAMs. Although
    not part of the Bally/Midway ROM set, there does exist a self-test
    ROM that you can install to test the RAMs and other game aspects.
    You should be able to find the test ROM by doing google searches;
    then all you'd need to do is pick up a working boardset on Ebay;
    generally less than $150. The RAM test is an audio "beep" code,
    so you would only need a speaker; the boadset has an audio amp,
    so no need for external amplification. Wire up a test fixture
    using pinouts for SI easily found through google searches; you
    would need an external power supply for -5VDC, +5VDC, and +12VDC
    (all voltages are needed for the DRAMs).

    Best Regards,

    John Hermann
    Buy, Sell, Trade, and Repair Video and Pinball Machines.
    Located near Dallas, TX.
    http://www.geocities.com/SiliconValley/Circuit/8393
     
  18. Look for the Bugtrap 8000 RAM tester. I believe it can be modified to
    test your RAM. I am looking to make an adapter for mine in fact, along
    with being able to test 2114s...

    John :-#)#

    --
    (Please post followups or tech enquires to the newsgroup) John's
    Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
    (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
    www.flippers.com "Old pinballers never die, they
    just flip out."
     
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