Agilent Technologies 856290216 service manual A4 LOG AMP/CAL OSC

Note	Because the cal oscillator circuitry on the A4 assembly is				such an	integral	part
	of	the	IF	adjustment, always check this assembly first, before checking the rest
	of	the	IF	Section. A faulty cal oscillator can cause many	apparent	“faults”	in

the rest of the IF Section.

Troubleshooting Using the TAM

Refer to Chapter 7, “General Troubleshooting,” for information on enabling the TAM for use with the HP 85623 spectrum analyzer.

When using Automatic Fault Isolation, the TAM indicates suspected circuits that need to be manually checked. Use Table 9-l to locate the manual procedure. Table 9-2 lists assembly test connectors associated with each Manual Probe Troubleshooting test. Figure 9-l illustrates the location of A4 and A5 test connectors. Figure 9-2 illustrates the levels and paths through the IF Section.

A 5 I F A4 LOG AMP/CAL OSC

J9

JIO, ,

(REVIIL CONNE

J7 J 6

"e

J 4

17 'P

'J4

J 6

J 3

Figure 9-1. A4 and A5 Test Connectors

IF Section 9-3