To Check The Low Voltage Power Supply - HP 54616B User And Service Manual

Service
Troubleshooting the Oscilloscope

To check the Low Voltage Power Supply

Disconnect the power cord, then set the oscilloscope on its side.
1
Connect the negative lead of the multimeter to a ground point on the
2
oscilloscope. Connect the power cord and turn on the oscilloscope.
Measure the power supply voltages at E10 through E15 on the system
3
board.
Power Supply Voltage Tolerances
Supply Voltage
+5.1 V
–5.25 V
+15.75 V
− 15.75 V
Figure 4-7
Low Voltage Power Supply voltage test points
If the +5.1 V measurement is out of tolerance, adjust the +5.1 V adjustment
on the power supply; if the –5.25 V measurement is out of tolerance, adjust
the –5.25 V adjustment on the power supply (see figure 4-2). The ±15.75 V
supplies are not adjustable and are dependent upon the +5.1 V supply.
4–40
Blown fuse
If the fuse is blown in the power supply, the power supply is defective. Replace
the power supply.
Tolerance
±153 mV (+4.947 V to +5.253 V)
±158 mV (–5.092 V to –5.408 V)
+1.260 V, –787 mV (+14.963 V to +17.010 V)
±787 mV (−14.963 V to −16.537V)