Agilent Technologies 4352B, Service Manual

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4. Check the A1 +5 VD LED
a. Remove the analyzer's bottom cover .
b. Turn the analyzer power on.
c. Look at the +5 VD LED . The +5 VD LED location on A1 CPU is shown in Figure 5-2. The
LED is normally on.
If the +5 VD LED is o, continue with the FIND OUT WHY THE A1 +5 VD LED IS NO T
ON STEADIL Y in this chapter .
If the +5 VD LED is on, the +5 VD power supply is veried with 95% condence level.
Continue with the Check A2 Seven LEDs in this procedure . If you want to conrm the last
5% uncertainty , perform steps in the next Measure the A1 +5 VD V oltage.
Figure 5-2. A1 +5 VD LED Location
Measure the A1 +5 VD V oltage
Measure the DC voltage on a test point A1TP8 (+5 VD) using a voltmeter . Check the voltmeter
reading is within 4.59 V to 5.61 V .
If the voltmeter reading is out of the limits , continue with the FIND OUT WHY THE A1 LED
IS NO T ON STEADIL Y.
If the voltmeter reading is within the limits , continue with the next step .
5. Check the A2 Seven LEDs
a. Remove the analyzer's top cover and shield.
b. Turn the analyzer power on.
c. Look at the A2 Seven LEDs . The A2 Seven LED locations are shown in Figure 5-3. Check
the LEDs are correctly on.
If two or more LEDs are o, continue with the TROUBLESHOO T A2 POST-REGULA TOR in
this chapter .
If the LEDs are correctly on, continue with the next Run the Internal T est 4: A2 POST
REGULA TOR.
5-4 P ower Supply T roubleshooting