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.
n
The 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.
n
Always 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