Service manual

PN 4237242C

4.13-3

SERVICE AND REPAIR PROCEDURES

LINEAR POWER SUPPLY CARD

Verification

1. Turn ON the instrument’s power. The Linear Power Supply card should produce voltages

immediately.

ATTENTION: The Linear Power Supply card is grounded to the Sensor Preamp Adapter card.

Since the Sensor Preamp Adapter card is not yet connected, you must use the associated black

reference test point with each voltage test point to get a proper reading.

2. Using your voltmeter, verify that you have:

r +15 Vdc ±0.75 V

r -15 Vdc ±0.75 V

r +240 Vdc ±24 V.

3. Turn OFF the instrument’s power.

4. Connect the four output connectors. P2 through P5 connect to J2 through J5,

respectively.

5. Turn ON the instrument’s power.

6. Measure the Hgb LED current supply by connecting the voltmeter negative lead to TP7

(CATHODE) and the positive lead to TP8 (ANODE), Figure 4.13-1. It should measure

approximately 2.2 Vdc.

Note: This voltage is dependent on other components and does not have a specific stated

range.

7. Close the rear panel door and replace the three captive thumbscrews.

8. Verify that the system reached the Main Menu. If it did not, turn the instrument’s power

OFF then back ON again.

9. Verify that the Hgb voltage is between 3.5 and 4.5 V by performing the Hgb Preamp

Adjustment procedure as directed under Heading 4.29.

10. Perform an SVP (Heading 5.1).