Granville-Phillips Series 330, Instruction Manual, Page: 71 / 76

8 Service and Maintenance
71
Series 330 Vacuum Gauge Controller
Instruction Manual - 330004 - Rev. 02
8.3.2 Power Supply Problems
If a problem persists after elimination of possible external causes by removing all cables except the
power cable, and thus appears to be in the controller, the power supplies should be checked first.
Use a standard Digital Volt Meter to check the test points listed in Table 8-2 for the outputs with
respect to ground. Test points are located near the top edge of the power supply module as shown
in Figure 8-1.
NOTE: It is permissible to remove the 34 pin bus cable to eliminate the
electrometer or display module as a source of the problem.
Table 8-1 Power Input Problems
Problem Possible Cause Corrective Action
1. The Power light does not
illuminate (all functions inoperative). 1. Power cord not plugged in.
2. No power to receptacle.
3. Controller input power fuse blown.
4. Defective power transformer T1,
power switch, or line filter.
1. Plug in power cord.
2. Restore power to receptacle.
3. Replace fuse with correct type and
value as indicated on rear panel.
4. Check secondary voltages of T1 at
connector of transformer P4 where it
plugs into the power supply module.
2. The Controller input power fuse
blows as soon as the power switch is
turned ON. 1. Incorrect power source.
2. Incorrect fuse rating.
3. Defective line filter, transformer,
power switch, or transient suppressor.
4. Defective component on the power
supply module.
1. Check the power source vs.
controller requirements. Connect the
controller to a proper source of
power or reset the selector card to the
voltage specified in Section 2.4.1.
2. Install the correct fuse as indicated
on the rear panel of the controller
and in Table 2-1.
3. Unplug the transformer secondary
from the power supply module (P4). If
fuse does not blow, proceed to the
next step.
4. Repair or replace the module.
Figure 8-1 Power Supply Module - Top View
(Controller Cover Removed)