3.3 TEST POINTS
Connectors and test points on the main circuit card are identified in Figure 3-8
and explained in the following paragraphs.
Door Lock Solenoid
Write Protect, Index
Track 00, Disk-in
JI0 Head Load Solenoid
Test Point FlD!tions:
TP3 Ground (0 VDC)
TP4 Differential Amp
TP5 Di fferential Amp
TP6 Erase Gate
TP7 Track 00 Sensor
L __ _
Figure 3-8 Location of Connectors
Figure 3-9 shows typical TP1/TP2 Pre-amp Waveforms.
Use these test points to
monitor the Read/Write head output.
The pre-ampll fier has two phase inverted
outputs that ranges from several tens to several hundreds of mUll volts peak-
For accurate waveform monitoring, a dual trace (2-channel) oscilloscope should be
used (with one channel set to the inverted ADD input mode) to monitor TPI and
TP2 as one waveform. The oscilloscope can be grounded at TP3.
TS-021-0n087 ••• 01