Commodore 1571 - Page 44

1571/C128D ALIGNMENT/REPAIR TEST
VERSION 1.2.1
ALIGNMENT/REPAIR TEST OPTION NINE - SIDE SELECT LOGIC
The Side Select Logic Test checks for proper operation of the Drive Side
Select Logic by turning each Head, (Upper and Lower), on individually.
SIDE SELECT LOGIC OPTION MENU
* Press (0) - Select Side 'O' (Lower)
* Press (1) - Select Side '1' (Upper)
* Press RETURN - Return to Menu
Displays Alignment/Repair Main Menu
Use a Scope or Meter to verify the Measured Signal with the
Expected Signal from the Side Select Control Logic Chart.
1571 SIDE SELECT LOGIC CHART
SIDE
CHECK IC
EXPECTED 1
SCOPE I
1 INCORRECT SIGNAL
SELECTED
PINS
SIGNAL |
MODE |
[ PROBABLE FAILURE
0 U9 - 4
LOW
DC
U9 - U8 - U17
0
U8 - 6
HIGH
DC
U8 - Q2
0
U7 - 4
LOW
DC
Q2 - U7
1
1
1
1
U9
U17
U8
U7
4
4
12
4
HIGH
LOW
HIGH
LOW
DC
DC
DC
DC
U9
U17
U8
Q3
U8
U8
Q3
U7
- U17
C128D SIDE SELECT LOGIC CHART
SIDE
SELECTED
CHECK IC
PINS
EXPECTED
SIGNAL
SCOPE
MODE
INCORRECT SIGNAL
PROBABLE FAILURE
0
0
0
U106 - 4
U108 - 20
U108 - 22
LOW
LOW
HIGH
DC
DC
DC
U106 - U108
U108 - BAD DRIVE
U108 - BAD DRIVE
1
1
1
U106 - 4
U108 - 20
U108 - 22
HIGH
HIGH
LOW
DC
DC
DC
U106 - U108
U108 - BAD DRIVE
U108 - BAD DRIVE
ALIGNMENT/REPAIR TEST OPTION TEN - LOAD DIAGNOSTIC MENU
* Insert Version 1.2 Diagnostic Diskette
* Press (8) - Load From Device » [8]
Loads Version 1.2 Diagnostic Menu From Device Number [8]
* Press (9) - Load From Device » [9]
Loads Version 1.2 Diagnostic From Device Number [9]
* Press RETURN - Return To Menu
Displays Alignment/Repair Main Menu
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