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Text File  |  1989-05-12  |  4KB  |  67 lines
  1. Oulu, Finland 1.1.-89                Kari Alakuijala (C) (Copyright)
  2.  
  3. This file is added for easy troubleshooting. Faults corrected here are the
  4. most likely ones. You must THINK what could be wrong in the circuitry, if
  5. these can't help you.
  6.  
  7. Trouble                                    Shoot
  8. -------                                    -----
  9.  
  10. Any                                       -Check the circuitry, especially
  11.                                            the solderings. Check wirings too,
  12.                                            if you didn't find any faults.
  13.                                            Check with installation manual
  14.                                            HARDRS2.TXT.
  15.  
  16. ST doesn't boot                           -Check all circuitry for bad
  17.                                            solderings. If none found, remove
  18.                                            all circuitry installed and try
  19.                                            to do the installation all over
  20.                                            again and try to be more careful
  21.                                            when doing it.
  22.  
  23. MIDI -interface doesn't work (properly)   -You are propably receiving 
  24.                                            characters via 2ND RS -port 
  25.                                            simultaneously, or check that
  26.                                            the switch is in the correct
  27.                                            position (i.e. 500kHz).
  28.  
  29. 2ND RS -interface doesn't work properly   -You are propably receiving 
  30.                                            characters via MIDI -port 
  31.                                            simultaneously, or check that
  32.                                            the switch is in the correct
  33.                                            position (i.e. variable fq).
  34.  
  35. 2ND RS -interface doesn't work            -A 1488 (transmitter don't work)
  36.                                            or a 1489 (receiver don't work)
  37.                                            you've installed might be broken.
  38.                                            If nothing else helps, buy new 
  39.                                            ones, these are cheap chips.
  40.  
  41.  
  42. Keyboard of ST doesn't work!               The clock rate 500kHz may be short
  43.                                            circuited. Check. Or, what even
  44.                                            worse: You have done the whole
  45.                                            installation to the wrong chip!
  46.                                            Physically the keyboard chip is
  47.                                            similar to midi chip, but their
  48.                                            functions on an ST differ
  49.                                            dramatically. Again: on the
  50.                                            instructions there is mentioned
  51.                                            that only the clock rate is taken
  52.                                            from the keyboard chip. All other
  53.                                            solderings and changes are done to
  54.                                            MIDI -chip, which is u20 (chip
  55.                                            number 20) on ST. Check the printed
  56.                                            circuit board layout to find the
  57.                                            text "u20" near 6850's. You will
  58.                                            notice that the keyboard chip is
  59.                                            a "u21". So you must start the
  60.                                            whole installation process all over
  61.                                            again after repairing the keyboard.
  62.                                            (Or perhaps you should disassemble
  63.                                            the whole circuit and let someone
  64.                                            other do it for you!)
  65.  
  66.  
  67.