Checking Of Signal Skew; Checking Of Signal Amplitude - Olivetti XZAC4219-03 PR2 plus Service Manual

CHECKING OF SIGNAL SKEW

4.3.6
This check must be carried out with the machine completely assembled, presetting and specifying the
magnetic device present on the machine in the Setup phase.
The source of signals must be only the following sheet:
- AMPLITUDE AND SKEW SAMPLE code 713483R for horizontal magnetic device.
Using an oscilloscope with memory, proceed as follows.
• Insert the "Amplitude and Skew Sample" sheet code 751884Z in the slot from the Skew Control side.
Record the signal read during movement of the head from right to left. The signal recorded must not have
a spread of more than 0.4 V. No action is required.
• Insert the "Amplitude and Skew Sample" sheet code 751884Z in the slot from the Jitter/Ampl. side.
Record the signal read during movement of the head from right to left. If the signal recorded does not
reach the value 4V, replace the head unit.

CHECKING OF SIGNAL AMPLITUDE

4.3.7
This check must be carried out in the same way as the previous check. Insert the sample sheet, suitably
oriented, so as to read the jitter and amplitude sample stripe; the printer will perform a read cycle before
ejecting the sheet. Using an oscillograph with memory, check amplitude of the signal read which must be
uniform and with a value of not less than 4V peak-to-peak for both magnetic devices.
The check must be carried out during the movement from right to left in the horizontal magnetic device.
4-28
Figure 4-2 View of board
XZAC4219-03