Agilent Technologies 856290216 service manual Isplay/Power Supply Section

13

D.isplay/Power Supply Section

The display/power supply section contains the A6 power supply, A6Al HV module, Al7 CRT driver, and Al8 CRT. Figure 13-1 illustrates the section block diagram. Table 13-1 lists signal

versus pin numbers for power cable Wl.

Troubleshooting Using the TAM

Blank Display (Using the TAM)

Blank Display

Blanking Signal

Display Distortion

Focus Problems

Intensity Problems

A6 Power Supply Assembly

Dead Power Supply

Line Fuse Blowing

Supply Restarting Every 1.5 Seconds (Kick Start)

Low Voltage Supplies

High Voltage Supplies

CRT Supply Dropping Out

Buck Regulator Control

DC-DC Converter Control

Power Up

Warning n The A6 power supply and A6Al high voltage assemblies contain lethal voltages with lethal currents in all areas. Use extreme care when servicing these assemblies. Always disconnect the power cord from the instrument before servicing these assemblies. Failure to follow this precaution can represent a shock hazard which may result in personal injury.

nThe voltage potential at A6AlW3 is +9 kV. If the cable must be disconnected, always disconnect it at the CRT with caution! Failure to properly discharge A6AlW3 may result in severe electrical shock to personnel and damage to the instrument. See procedure 2, “Al Front Frame/Al6 CRT,” in Chapter 4, “Assembly Replacement.”

I Do not discharge the CRT second anode directly to ground, with the A6Al high voltage cable connected. This can damage the Al7 CRT driver assembly. Always discharge through a high resistance, such as a high voltage probe.

nAlways use an isolation transformer when troubleshooting either the A6 power supply or the A6Al HV module. When using an isolation transformer, connect a jumper between AGTPlOl and A6TP301. This connects the circuit common to earth ground. Remove this jumper when the isolation transformer is not used.

Display/Power Supply Section 13-l