TEXT   48

RAM Failure is indicated by a sequence

Guest on 15th May 2022 04:26:53 AM

  1.  RAM Failure is indicated by a sequence of from 1 to 6 tones.
  2.  A low-frequency tone is heard for each good RAM chip.  A much
  3.  lower frequency is heard for a  failing RAM chip.  The sequence
  4.  stops with the last failing RAM chip.  To restart the sequence,
  5.  press the Reset pushbutton on the game PCB or set the self-test
  6.  switch to off, then again to the ON position.  Identify the bad
  7.  RAM chip with the table below.  Example:  Three tones, then
  8.  a tone of much lower frequency indicates failure of RAM chip R4.
  9.  
  10.     Tone     RAM Chip Location
  11.    ----------------------------
  12.       1            D2
  13.       2            E2
  14.       3            M4
  15.       4            R4
  16.       5            N4
  17.       6            P4
  18.  
  19.  ROM/PROM Failure is indicated by two columns or lines of numbers
  20.  in the upper left-hand corner of the display.  The number in the
  21.  left column or first line indicates the failing ROM/PROM chip(s).
  22.  Identify the bad ROM/PROM with the table below.
  23.  The number in the right column or second line indicates the
  24.  failing data bit of the failing ROM/PROM.  Identify the bad bit
  25.  with the second table below.  If more than one bit is failing,
  26.  the displayed number(s) are hexadecimal combinations of the
  27.  numbers shown below.  Examples:
  28.        1) If bits D2 and D3 fail, C is displayed.
  29.        2) If bits D2, D3 and D7 fail, 8C is displayed.
  30.        3) If bits D4 and D5 fail, 30 is displayed.
  31.        4) If bits D1, D3, D5 and D6 fail, 6A is displayed.
  32.  
  33.    Displayed No.       Failing ROM/PROM
  34.   -----------------------------------------------------
  35.                  -05 & -06 PCB       -03 & -04 PCB
  36.  
  37.         0            N/P3          N/P3  K4,L4
  38.         1            N/P3          N/P3  K4,L4
  39.  
  40.         2             J2            F1   F2,L1   F2,H1
  41.         3             J2            F1   F2,L1   L2,L1
  42.  
  43.         4             H2           D/E1  H2,J1   H2,J1
  44.         5             H2           D/E1  H2,J1   M2,M1
  45.  
  46.         6            E/F2           C1   K1,J2   J2,K1
  47.         7            E/F2           C1   K1,J2   N2,N1
  48.  
  49.    Displayed No.     Failing Bit
  50.   -------------------------------
  51.          1               D0
  52.          2               D1
  53.          4               D2
  54.          8               D3
  55.         10               D4
  56.         20               D5
  57.         40               D6
  58.         80               D7
  59.  
  60.  
  61.    RAMSEL signal failure is indicated by a BANK ERROR or
  62.    PAGE SELECT ERROR message at lower middle of display.

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