
4-4 Troubleshooting
Test Set Fails to Power Up
Chapter 4 — Troubleshooting
4-2
PN: 10410-00730 Rev. D
MN469xC Series Multiport Test Set MM
4-4
Troubleshooting
Test Set Fails to Power Up
If the MN469xC test set fails to power up when connected to an AC power source and the
Power
key is pressed,
perform the power supply checks described below.
Line Source and Interface Checks
1.
Verify that the AC power source is providing stable power at the correct line voltage.
2.
Verify the AC power cord is in good condition.
3.
Verify the power line fuse is installed and that is not blown (open).
Power Supply Voltage Check
1.
Turn off the test set and disconnect the AC power cord from the instrument. Ensure that all external
front and rear panel cable connections to the test set are also disconnected.
2.
Remove the top cover.
•
Refer to
Section 5-3 “Removing the Covers” on page 5-2
3.
Re-connect the power cord to the test set and turn it on.
4.
Using a digital multi-meter or oscilloscope, measure the expected DC power supply voltages on the 4-Port
Test Set Control PCB at the P4 connector pins or test points listed in
below.
•
Figure 4-1, “4-Port Test Set Control PCB P4 Connector Location” on page 4-3
point locations.
5.
If any of the DC voltage is much lower than the expected value, replace the power supply
(part number 3-40-183).
•
Refer to
Section 5-8 “Power Supply Replacement” on page 5-8
Warning
Hazardous voltages are present inside the instrument when AC line power is connected. Turn off the
instrument and disconnect the AC line cord before removing any covers. Troubleshooting or repair
procedures should only be performed by qualified service personnel who are fully aware of the
potential hazards.
Note
The MN469xC is designed to automatically sense and operate with AC line voltage in the range of
85 to 264 Volt AC, with a frequency range of 47 to 63 Hz.
Table 4-1.
Power Supply Voltages
Measured Pin
Common Pin
Expected DC Voltage
P4 pin 1 (or TP7)
P4 pin 2
15 V
P4 pin 4 (or TP6)
P4 pin 2
+15 V
P4 pin 5 (or TP5)
P4 pin 2
5.5 V
P4 pin 8 (or TP2)
P4 pin 2
+5.5 V
Содержание VectorStar MN469 C Series
Страница 2: ......
Страница 6: ...Contents 4 PN 10410 00730 Rev D MN469xC Series Multiport Test Set MM Table of Contents Continued...
Страница 77: ......