Check The Green Leds On A8; Measure The Post Regulator Voltages - HP 8753E Service Manual

Check the Green LEDs on A8

Remove the top cover of the analyzer and locate the A8 post regulator; use the
location diagram under the top cover if necessary. Check to see if the green
visible without removing the PC board stabilizer).
If all of the green LEDs on the top edge of A8 are on, there is a 95%
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confidence level that the power supply is verified. lb confirm the last 5%
uncertainty of the power supply, refer to "Measure the Post Regulator
Voltages" (next).
If any LED on the A8 post regulator is off or Eashing, refer to "If the Green
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Measure the Post Regulator Voltages

Measure the DC voltages on the test points of A8 with a voltmeter. Refer to
Figure 5-3 for test point locations and Table 5-l for supply voltages and limits.
AGND
Figure 5-3. A8 Post Regulator 'l&t Point Locations
Power Supply Troubleshooting