Vector 4 - Page 149

VECTOR GRAPHIC, INC.
1. Make sure that system is turned off, with no diskette in drive,
2. Disconneet drive mountings and slide drive forward out of frame to
access drive logic PCBA.
In the following step, refer to Exhibit III-3 for location of test points on drive
logic PCBA. -- *
3. Connect oscilloscope probes per the following speéifications:
Channel A: Test Point 1
Channel B: Test Point 2
Ground: Test Point 10
Read Differentially: A plus B, B inverted
Time Base: 20 msec per division
External Trigger: Test Point 7, positive edge
Vertical Display: 0.1 volt per division
3. Turn system on and insert alignment diskette into drive to be tested.
4, Select Head 00, Track 36.
In the following steps, neither cat's eye pattern should be less than 75% the
size of the larger pattern.
If pattern at any track of either head is out of proportion, the drive must be
adjusted. Complete the procedure listed here, then go to 3.3, Adjust Floppy
Drive.
If all patterns are within proportions, drive alignment is o.k.
5. Adjust oscilloscope to display cat's eye pattern (see Exhibit IlI-4). Make
sure that cat's eye patterns are within correct proportions. -
6. Step drive head to Track 00, then back to Track 36. Make sure that
cat's eye patterns are within correct proportions.
7. Step drive head to Track 52 (or higher track), then back to Track 36.
Make sure that cat's eye patterns are within correct proportions.
I 3-4 7200-0001 09-01-82