Cats Eye Alignment Check And Adjustment; Circuit Board Assembly - Tandon TM848-1 Operating And Service Manual

E.
Set up the oscilloscope, as follows:
Voltage: 2 volts per division
Time Per Division: 20 milliseconds
Trigger: Negative, Channel A, R33
Note
For the TM848-1 single-sided drive, trigger off of R33. For the TM848-2 double-sided drive,
trigger off of Test Point 12, with the exception of azimuth, which must be triggered off of R33
(see Figure 2-1). '
R133
MIg
0
8
M2
cr.
00
o
1ttttttttttttft . . . .
- .;.,;P6:.....-_-r-
P
,;"..,14
00
00
(I<Il
(IO
~
. . P4
~P5
M3
C>O
o
M4
2S_
DC 00
00
RI
~ ALTERNATE TEST POINT,INDEX TRIGGERING
0-3-0
NP 00 y
DSI 00&00 DS2
WP -
TPll0erz.,.
P2 P3Pl0 PI PllP12
ffiffftf11TTiil
TP2
TPI
1
- Jo
TP3
P8 P9
1i1iftttif
00 DSI
lb 0
00 DS2
2b 0
00DS3
3b 0
00DS4
4b 0
o
OTP8
OTP10
gDL
P7
00
P13
Figure 2-1
Circuit Board Assembly
F. Adjust R133 until a reading of 166.667 milliseconds is achieved from leading edge to leading
edge of the index pulses.
G. If the drive motor's speed cannot be adjusted, see Section IV, Troubleshooting Guide.
2.2 CATS EYE ALIGNMENT CHECK AND ADJUSTMENT
The Cats Eye (C. E.) alignment procedure locates the read/write head at the oroper radial distance
from the hub center line, ensuring that the track location is accurate(seeFig;ure 2-2). This adjustment
is necessary only after servicing or if diskette interchange problems are suspected.
2-2