Agilent Technologies 856290216 service manual Blank Display

2.All of the power-supply indicator LEDs along the edge of the A2 controller assembly should be lit.

3.The rear-panel CRT +llO VDC ON indicator should also be lit.

4.Connect the TAM probe cable to A2Jll.

5.Press (m), SOFT KEY t3, a, SOFT KEY #I. (The top soft key is #l.)

6.The yellow LED next to A2Jll should blink approximately ten times. If the LED fails to blink correctly, troubleshoot the digital section of the A2 controller assembly.

7.Move the probe cable to A2J202. Press SOFT KKY ti and wait 5 seconds.

8.Press SOFT KEY t4 . The results should be sent to the printer.

9.Move the probe cable to A2J201, press SQFT KEY #I and wait 5 seconds.

16. Press SaFT KEY 84 . The results will be sent to the printer.

11.If a failure is indicated in any of these tests, the fault lies on the A2 controller assembly. To obtain more information:

a.Press the down arrow key one less time than the test number. (For example, press it twice for the third test on the list.)

b.Press SOFT KEY t3 , then SOFT KEY #4, and when the printout is complete,

SOFT KEY t6.

12.If no failures were indicated in testing the A2 controller, move the probe cable to A17J4.

13.Press SOFT KEY #i and wait 5 seconds.

14.Press SOFT KEY #4 . The results will be sent to the printer.

15.If no failure is indicated in the printout, check the high-voltage supplies as described in “High Voltage Supplies” in this chapter.

Blank Display

1.If the LED above the front-panel LINE switch is lit, most of the A6 power supply is functioning properly.

2.Carefully check the voltages on the front-panel PROBE POWER jack. Be careful to avoid shorting the pins together. See Figure 13-3.

3.Check that the fan is operating. If the PROBE POWER voltages are correct, and the fan is turning, the A6 power supply is probably working properly.

4.If the rear-panel CRT +llO VDC ON LED is lit, the high-voltage supplies should also be operating. (The high-voltage supplies will be turned off if the HV-SHUT-DOWN line is low.) The A6 power supply feeds +5 V to the A2 controller through Wl. The A2 assembly distributes this +5 V to the Al7 CRT driver through W7. Al7 sends +5 V back to A6 as the HV-SHUT-DOWN signal on W8. As a result, A2, A17, Wl, W7, and W8 must all be in place for the high-voltage supplies to operate.

13-6 Display/Power Supply Section