
Troubleshooting and Block Diagrams 8712ET/ES and 8714ET/ES
Category 1 Failures: Dead or No Display RF Network Analyzers
4-8 Service Guide
5. If the green LED is on, and the red LED is blinking
The power supply is in shutdown. Remove the power supply/display assembly from
analyzer, plug it in and switch the analyzer's line power on.
a. If the red LED is still blinking
Replace the power supply.
b. If the red LED is now off
Go to “Removing the Assemblies” on page 4-9 (the supply is most likely being loaded
down by another assembly).
Measuring the Power Supply Voltages
Remove the backplane cover from the rear panel. Figure 4-3 shows the pinout for J1. There
are four main supplies, each with its own return, plus the standby voltage which powers
the nonvolatile SRAM on the CPU board. Measure the voltages with a voltmeter. Values
should be within 5% of nominal for all but the +13 V supply.
Figure 4-3 Power Supply Connector, as Viewed from Rear Panel
1. If the voltages are not correct
Remove the power supply/display assembly, plug in the AC power, and switch the
analyzer's line power on. Check the four power supply LEDs visible from the right side
of the display enclosure (as viewed from the front).
a. If one or more LEDs are off
Replace the power supply.
b. If all the LEDs are on
Reseat the power supply/display assembly, making sure there's a good connection to
the rear panel. Measure the voltages again. If the problem persists, check connectors
on the power supply and on the backplane board.
Commenti su questo manuale