HP 8560E Service Manual page 639

Display/Power Supply Section
Power Supply
Power Supply
The power supply section contains the A6 power supply and, in 8560E
instruments, the A6A1 HV module.
the power supply block diagram.
versus pin numbers for power cable W1.
The A6 power supply in 8560E and 8560EC instruments, and the
WARNING
A6A1 high voltage assembly in 8560E instruments, 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.
The voltage potential at A6A1W3, in 8560E instruments, is +9 kV.
If the cable must be disconnected, always disconnect it at the
CRT with caution! Failure to properly discharge A6A1W3 may
result in severe electrical shock to personnel and damage to the
instrument. See procedure 2 in Chapter 3.
Do not discharge the CRT second anode directly to ground,
with the A6A1 high voltage cable connected. This can damage
the A17 CRT driver assembly. Always discharge through a high
resistance, such as a high voltage probe.
Always use an isolation transformer when troubleshooting
either the A6 power supply or the A6A1 HV module. When using
an isolation transformer, connect a jumper between A6TP101
and A6TP301. This connects the circuit common to earth
ground. Remove this jumper when the isolation transformer is
not used.
638
A6 Power Supply Assembly ............................................
Dead Power Supply ......................................................
Line Fuse Blowing .......................................................
Supply Restarting Every 1.5 Seconds (Kick Start) ....
Low Voltage Supplies ...................................................
High Voltage Supplies (8560E only)............................
CRT Supply Dropping Out (8560E only) ....................
Blanking Signal (8560E only)......................................
Buck Regulator Control ...............................................
DC-DC Converter Control ...........................................
Power Up ......................................................................
Figure 12-7 on page 639
Table 12-3 on page 640
illustrates
lists signal
page 642
page 642
page 644
page 644
page 644
page 645
page 646
page 647
page 647
page 648
page 648
Chapter 12