iSys V12 Thermal Printer - Manual (Page 35)

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marks. Do not decrease the voltage to the point where it changes from -5.100V- to -0.000V-.
7. Once the plotter stops on the TOF marks, twenty consecutive tests to detect the marks
should be performed. If the plotter fails any of these attempts, another adjustment should be
made either to increase or decrease the sensitivity of the sensor, and the twenty tests should be
repeated.
8. Swing the rear panel upwards and replace the two 6/32 x 2”Philips pan head screws located
at in the top two corners of the rear panel.
Replacing the rear cooling fan
1. Open the back of the plotter as described in this chapter.
2. Remove the four nylon locknuts shown in Figure 7-23.
3. Detach the fan cable from its header on the main board, shown in Figure 7-25.
4. Replace the fan and reverse steps to reassemble, taking care not over-tighten nuts.
NOTE: Install fans so that the air flow is from inside to outside.
Replacing the bottom cooling fan
1. Open the bottom panel as described in this Chapter.
2. Remove the cable ties securing the fan to the 24 Volt wire harness.
3. Remove the four nylon locknuts shown in Figure 7-24.
4. Detach the spade connectors of the fan cable from the 24 Volt power supply terminal block
shown in Figure 7-27. Note that the spade connectors are bent towards the terminal block.
Ensure that the connectors are in the same position when they are replaced.
5. Replace the fan and reverse steps to reassemble taking care not to over-tighten the nuts.
NOTE: Install fans so that the air flow is from inside to outside.
Measuring and adjusting 24 Volt power supply voltage
1. Open the back panel as described in this chapter to gain access to the main logic board.
2. Using a voltmeter, measure at pins 1 and 3 the test point J2 on the main logic board.
3. Remove the right side panel as described in this chapter.
4. With the voltmeter attached, adjust the 24 Volt potentiometer shown in Figure 7-31 to the
appropriate voltage.
5. Replace the rear and right side panels.
CAUTION: Do not adjust the power supply higher than 25 Volts. This may damage the plotter.