5-10 Service Guide
Power Supply Troubleshooting 8719ET/20ET/22ET
If the Red LED of the Preregulator (A15) Is On 8719ES/20ES/22ES
RF Network Analyzers
Verify the Preregulator (A15)
Verify that the preregulator (A15) is supplying the correct voltages to the post regulator
(A8). Use a voltmeter with a small probe to measure the output voltages of A15W1’s plug.
Refer to Table 5-2 and Figure 5-6.
• If the voltages are not within tolerance, replace A15.
• If the voltages are within tolerance, A15 is verified. Go to “Check for a Faulty Assembly”
on page 5-11.
Table 5-2 Output Voltages
Pin A15W1P1
(Disconnected)
Voltages
A8J2
(Connected)
Voltages
A15
Preregulator
Mnemonic
1 N/C N/C N/C
2 +100 to +125 +100 to +125 (not used)
3,4 +22.4 to +33.6 +17.0 to +18.4 +18 V
5,6 −22.4 to −33.6 −17.0 to −18.4 −18 V
7 N/C +7.4 to +8.0 N/C
8 +9.4 to +14 +7.4 to +8.0 +8 V
9,10 −9.4 to −14 −6.7 to −7.3 −8 V
11 +32 to +48 +24.6 to +26.6 +25 V
12 N/C +24.6 to +26.6 N/C
NOTE: The +5 VD supply must be loaded by one or more assemblies at
all times, or the other voltages will not be correct. It connects to the
motherboard connector A17J3 Pin 4.
To Next Page
Loading...
Need help?
General
