Agilent Technologies 8590 Series Service Manual page 272

Troubleshooting the IF Section
Troubleshooting the A15 Motherboard Assembly
Table 5-6 A15 Motherboard Mnemonic Descriptions
Mnemonic
21.4 MHz IF 21.4 MHz IF
+10V +10 V Supply
+12V +12 V Supply
+15VF +15 V Supply
+5V +5 V Supply
−15V −15 V Supply
−8VT −8 V Temperature
Compensated
Supply
ACOM Analog Common
ADC_SYNC A/D Conversion
Synchronization
ADR0-ADR4 Address 0-4
ANA_TEST Analog Test
AUX_IF Auxiliary IF
AUX_IF_BP Auxiliary IF Back
Panel
272
Full Name
The 21.4 MHz IF signal between the A9 Third
Converter assembly and the detector on the A14
Log Amplifier assembly.
The A7 Analog assembly provides a +10 V bias
supply for the LC bandwidth filters on the A11/A13
bandwidth filter assemblies.
+12 V supply for the A2 Display and the RS-232
option, referenced to DCOM.
+15 V power supply, referenced to ACOM.
+5 V power supply, referenced to DCOM.
−15 V power supply, referenced to ACOM.
Provides −8 V from the temperature-compensated
(TC) power supply on the A14 Log Amplifier
assembly to the A7 Analog Interface assembly. The
A7 provides temperature-compensation for the
IFG4-IFG6 and the Log/Lin control lines using the
−8 VT as a TC reference.
A common ground for all analog circuitry.
A positive-going signal that indicates when the
main ADC on the A16 Video/Processor assembly has
started an A/D conversion. ADC_SYNC resets the
peak detectors located on assemblies installed in
the 8590L, 8591C, 8591E, 8593E, 8594E, 8595E,
8596E, and 8594Q card cage.
Input/Output (IO) address lines.
Provides a series of test signals from A7 Analog
Interface assembly to A16 Processor/Video
assembly during instrument calibration and
troubleshooting. (Refer to the A7 Overview Section)
An uncorrected, buffered 21.4 MHz IF signal from
the output of the A13 bandwidth filter assembly to
the four card-cage slots.
An uncorrected, buffered 21.4 MHz IF signal from
the output of the A13 bandwidth filter assembly to
J17, AUX IF OUTPUT.
Description
Chapter 5