Service manual

Section I: Imagesetter
Diagnostics 3-71
6. If the voltage reading is wrong, check the voltage coming into the solid
state relay (SSR). See Figure 3-3.
a. Using a DVM, measure the AC voltage across the following two points:
Pin 2 (solid state relay) At 110 V ⇒ 110 V
Pin 1 (volt sensing relay) At 220 V ⇒ 110 V
If the voltage reading is wrong, skip to Step 7.
b. If the voltage reading is good, check the input side of the SSR. Using a
DVM, measure the DC voltage across the following two points:
Pin 3 (solid state relay) +24vdc
Pin 4 (solid state relay) +24vdc
c. If the DC voltage reading is good, a defective SSR is the probable
cause. Replace the SSR.
If the voltage reading is wrong, go to Step 7.
7. A bad DC voltage reading may indicate a defective vacuum module PCB or
a problem with the digital signal from the DEC board.
a. Check the output of the transformer using a DVM to measure the AC
voltage across the following two points:
0V Outside--Gray Conn At 110 V ⇒ 110 V
115V Outside--Gray Conn At 220 V ⇒ 110 V
8. A good voltage reading may indicate a defective or miswired volt sensing
relay. Replace the volt sensing relay if the wiring is correct.
9. If the voltage reading is wrong, check the transformer input. Using a DVM,
measure the AC votage across the following two points:
0V Outside--Gray Conn At 110 V ⇒ 110 V
115V Outside--Gray Conn At 220 V ⇒ 220 V
10. A good voltage reading may indicate a defective transformer. Replace the
transformer.
11. If the voltage reading is wrong, check the wiring to the transformer.
3.5.1 Volt Sensing Relay Adjustment Procedure
This procedure ensures that systems operating at 220V have vacuum power
stepped down to 110V. which the vacuum pump requires.
To adjust perform the following steps:
1. Turn the system off and unplug it.
2. Locate and remove the electronics box at the bottom of the system (see
Section 4.8, Vacuum in Chapter 4, Imagesetter Component Removal/
Replacement Procedure).