Aeroflex 3500A, Maintenance Manual, Page: 30 / 169

2-6
S u b j e c t t o E x p o r t C o n t r o l , s e e C o v e r P a g e f o r d e t a i l s .
TROUBLESHOOTING TABLE
NOTE
The Troubleshooting Table lists common malfunctions found during normal
operation of the Test Set. The tests or inspections and corrective actions
should be performed in the order listed. Failure to do so may result in
troubleshooting recommendations that replace working items.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1 External DC Power Supply failure
Step 1. Connect the External DC Power Supply to a verifiable AC Power Source
and verify the LED is lit.
 If incorrect, replace the External DC Power Supply.
Step 2. Using a DMM on the External DC Power Supply output, 18 Vdc
(
± 1 Vdc).

If incorrect, replace the External DC Power Supply.
2 POWER Indicator does not illuminate
Step 1. Connect the External DC Power Supply to a verifiable AC Power Source
and verify the LED is lit.
 If incorrect, replace the External DC Power Supply.
Step 2. Using a DMM on the External DC Power Supply output, 18 Vdc
(
± 1 Vdc).

If incorrect, replace the External DC Power Supply.
Step 3. Verify the Battery is installed.
 If incorrect, install the Battery (para 2-4A).
Step 4. Verify the Fuse is not blown.

If incorrect, replace the Fuse (para 2-4B).
Step 5. Remove any external power sources from the Test Set. Using a DMM,
verify 11.1 Vdc Nominal at the Battery Connector (Red wire).
 If incorrect, replace the Battery (para 2-4A).
Step 6. Connect the External DC Power Supply to the Test Set. Using a DMM,
verify 12.6 Vdc at the Battery Connector (Red wire).
 If incorrect, replace the Power Supply PCB Assy (para 2-4D).
Step 7. Troubleshoot the circuit between the Power Supply PCB Assy and the LCD
Assy.

Probable source of failure is the Power Supply PCB Assy.

Probable source of failure is the RF Digitizer PCB Assy.
 Probable source of failure is the Multi-Function PCB Assy.
 Probable source of failure is the LCD Assy.