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  • H12761 TWINAX ATTACHED DEVICES DROPPING OFF LINE

    From Louis Ohland@21:1/5 to All on Fri Nov 12 13:30:51 2021
    5250 EMULATION ADAPTER/A OPTION KITS
    P/N 64G3496 (EMEA), P/N 64G3494 (USA), AND
    P/N 64G3495 (FRU) SHIPPED AFTER MAY 1993 MAY
    CAUSE OTHER TERMINALS OR SYSTEMS TO DROP OFF THE
    COMMUNICATIONS LINE WHEN THE 5250 ADAPTER CARD'S
    SYSTEM UNIT IS POWER OFF. THE LINE MAY DROP
    MOMENTARILY OR MAY REMAIN DOWN UNTIL POWERED OFF
    UNIT IS TURNED BACK ON. THIS PROBLEM MAY OCCUR
    IN ANY MICROCHANNEL BUS MACHINE.

    THIS PROBLEM MAY ALSO SHOW UP IF CUSTOMER IS
    EXPERIENCING TROUBLE TRYING TO ESTABLISH HOST
    SESSIONS WITH OTHER TWINAXIAL DEVICES ON THE
    LINE. IF A POWERED OFF 5250 CARD IS ON THE
    SAME LINE AS THE TROUBLED DEVICE, CHECK THE
    LEVEL OF THE 5250 CARD FOR THE PROBLEM CARD
    ASSEMBLY LISTED BELOW.

    AFFECTED 5250 ADAPTERS CAN BE IDENTIFIED BY
    CARD ASSEMBLY P/N 64G3513 ON A LABEL ON THE CARD.
    AFFECTED CARDS CAN ALSO BE IDENTIFIED BY THE FRU
    P/N 64G3495 LABELED ON THE BLUE CARD HOLDER.
    THIS LEVEL OF CARD IS THE ONLY CARD WITH THE
    PROBLEM.

    NOTE: P/N 64G3513 IS A MANUFACTURING PART NUMBER
    AND NOT THE FRU NUMBER.

    AFFECTED CARDS CAN BE REWORKED TO NEW LEVEL CARD
    ASSEMBLY P/N 64G3508 IN THE FIELD BY REMOVING
    SMT (SURFACE MOUNT TECHNOLOGY)
    RESISTORS R35 AND R34. THESE CAN BE REMOVED
    BY USING NEEDLE NOSE PLIERS TO BREAK OFF THESE
    RESISTORS. THE PADS FOR THESE COMPONENTS MAY
    COME OFF DURING THIS OPERATION BUT THIS WILL
    NOT AFFECT THE PERFORMANCE OF THE CARD.
    R34 AND R35 ARE LABELED ON THE CARD AND ARE
    LOCATED NEAR THE BOTTOM RIGHT SIDE IF THE CARD
    BELOW DIODES D3,D5,D6. BOTH OF THE RESISTORS
    SHOULD BE COMPLETELY REMOVED.

    FRU STOCK IS BEING REWORKED TO NEW LEVEL
    P/N 64G3506 AND WILL BE AVAILABLE THROUGH NORMAL
    CHANNELS.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From IBMMuseum@21:1/5 to All on Fri Nov 12 20:35:50 2021
    AFFECTED CARDS CAN BE REWORKED TO NEW LEVEL CARD
    ASSEMBLY P/N 64G3508 IN THE FIELD BY REMOVING
    SMT (SURFACE MOUNT TECHNOLOGY)
    RESISTORS R35 AND R34. THESE CAN BE REMOVED
    BY USING NEEDLE NOSE PLIERS TO BREAK OFF THESE
    RESISTORS. THE PADS FOR THESE COMPONENTS MAY
    COME OFF DURING THIS OPERATION BUT THIS WILL
    NOT AFFECT THE PERFORMANCE OF THE CARD.
    R34 AND R35 ARE LABELED ON THE CARD AND ARE
    LOCATED NEAR THE BOTTOM RIGHT SIDE IF THE CARD
    BELOW DIODES D3,D5,D6. BOTH OF THE RESISTORS
    SHOULD BE COMPLETELY REMOVED.

    Wow, this EC "rework" notification really amazes me - I've noticed color coding on the edge of 5250-related adapter PCB - I wonder if it is a quick visual identifier for an EC.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)