Commodore 1541 Maintenance Manual page 12

3. Connect AC power cord between J9 on VIC-1541 and AC
outlet.
IWARNINGI
• USE EXTREME CARE TO AVOID CONTACT WITH
FRAME COMPONENTS. HIGH AC VOLTAGE
POTENTIALS ARE PRESENT DURING
CALIBRATION. THESE VOLTAGE POTENTIALS
CAN CAUSE BODILY INJURY OR EVEN DEATH.
4. Place VIC-1541 power switch to ON.
5. Apply power to VIC-20/COMMODORE 64.
6. If a VIC-20 is the computer being used, enter the
following command:
OPEN 15,8,15,"UI-":CLOSE 15<Return>
7. Insert disk which will be used as the alignment standard
into the VIC-1541.
8. Enter the following program into the computer. This
program will place the head on track 16 and will leave the
drive motor running.
10 OPEN 15,8,15,"U+":OPEN 2,8,2,"#":0PEN 8,8,8,"#h
20 PRINT #15,"B-P:";8;0:PRINT #15,"UA:";2;0;16;1
30 FOR X~l TO 9:READ Y
40 PRINT #8,Y;
50 NEXT X
60 PRINT #15,"M-E"+CHR$(0)+CHR$(5)
70 STOP
80 DATA 173,0,28,9,4,141,0,28,96
9. Type RUN<Return>.
10. Loosen two screws (Figure 5-2, Item 1) securing stepping
motor housing to drive unit. Do not remove screws. Screws
should be just loose enough to permit rotation of the
stepping motor housing.
11. Rotate stepping motor housing while observing DVM
display. Voltage reading on DVM will increase or decrease
while rotating stepping motor housing. Correct position for
stepping motor housing is the position which produces the
largest voltage reading on DVM. Tighten the two screws when
this position is reached.
12. Turn off DVM, disk drive and computer.
13 •• Disconnect all cables and test accessories from disk
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