Agilent Technologies 4395A, Service Manual

Page: 230 / 343

TROUBLESHOOT THE A51 GSP and A52 L CD
Use this pro cedure when the LCD(Liquid Crystal Display) is unacceptable, or not b eing
brigh t.
1. Run the Internal T est 3: A51 GSP .
The A51 GSP can b e c hec k ed using the in ternal test 3: A51 GSP , if the test fails, the 4
Ch 1
5
and 4 Ch 2 5 LEDs blink sev eral time and a few b eeps sound at the end of the test. Then the
analyzer returns the con trol settings to the p o w er-on default setting v alues.
a.
Press 4
PRESET
5, 4
SYSTEM
5,
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
SERVICE MENU ,
NNNNNNNNNNNNNNNNN
TESTS , 4
3
5, 4
x1
5,
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
EXECUTE TEST to run the
in ternal test 3. When this test starts, 4 Ch 1 5 LED and 4 Ch 2 5 LED are turned o.
b. Chec k the 4
Ch 1
5 and 4
Ch 2
5 LEDs and the b eeps at the end of the test.
If no b eep sound and the LEDs don't blink, the A51 GSP is probably w orking. Con tinue
with the next Che ck the Two LEDs on A51 GSP.
If a b eep sounds and the LEDs blink one time, the A51 GSP c hip is faulty . Replace the
A51 GSP .
If t w o b eep sound and the LED blinks t w o time, the A51 GSP's DRAM is faulty .
Replace the A51 GSP .
If three b eep sound and the LED blinks three time, the A51 GSP's VRAM is fault y .
Replace the A51 GSP .
2. Check the A52 LCD(Liquid Crystal Display)
The A52 LCD can b e tested using the in ternal test 70 to 74.
a.
Press 4 PRESET 5, 4 SYSTEM 5,
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
SERVICE MENU ,
NNNNNNNNNNNNNNNNN
TESTS , 4 7 5, 4 0 5, 4 x1 5,
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
EXECUTE TEST
NNNNNNNNNNNNNNNNNNNNNNNNNN
CONTINUE to
run the in ternal test 70, and run the other tests with the same manner.
b. If an y defects on the LCD, replace the LCD.
c. If no correct patterns are display ed, c hec k the A54 In v erter.
8-12 Digital Control Troubleshooting