2 Check High Voltage Supply

a. Set the POWER switch to OFF (button out).

b. Set the dc voltmeter to a range of at least -2500 V dc and connect the volts lead to chassis ground. Remove the crt base-socket cover and connect the common lead of the dc voltmeter to pin 2 on the socket.

c. Set the POWER switch to ON (button in).

d. CHECK—High Voltage Supply dc level is -1900 V to -2100 V.

e. Set the POWER switch to OFF (button out).

i. Re-install the High-Voltage shield (see the "HighVoltage Shield" reinstallation procedure in Section 6) or the protective shield , depending on your instrument.

j. CHECK—Voltage levels of the remaining power supplies listed in Table 5-2 are within their specified limits.

Table 5-2 POWER SUPPLY LIMITS AND RIPPLE

Power Supply

Test Point

Reading (Volts)

P-P Ripple (mV)

-8.6 V

TP500

-8.56 to -8.64

<10

+5 V

W985

4.75 to 5.25

<10

+ 8.6 V

W975

8.34 to 8.86

<10

+30 V

W965

28.5 to 31.5

<50

+ 100 V

W966

95 to 105

<200

k. Connect the test oscilloscope, using a 1 x probe, to the first test point indicated in Table 5-2 and connect the probe ground lead to TP501.

I. CHECK—Ripple amplitude of the dc supply is within the typical value given in Table 5-2.

m. Repeat parts k and I for each test point in Table 5-2.

f. Disconnect the voltmeter leads and re-install the crt base-socket cover.

g. Set the POWER switch to ON (button in).

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