Agilent Technologies 54835A Service Manual page 93

Check +15 V Bias and Remote Inhibit cabling.
E
If the oscilloscope will not power up, check all cabling to troubleshoot and correct the problem.
Figure 5-4 shows the routing of the +15 V Bias and Remote Inhibit signals from the front panel
to the power supply. The power supply is on only when the remote inhibit signal is between
+1 V and +5 V. A problem could be caused by a faulty cable or bad connector anywhere in this
path. Check all the cables and connections and replace any at fault.
Figure 5-5
Routing of +15 V Bias and Remote Inhibit Signals
Replace the power supply.
F
1 If the +15 V bias is correct, but the instrument will not power up with a 196-220 Ω resistor,
replace the power supply. Chapter 6 explains how to remove and replace the power
supply.
2 Re-assemble the instrument and apply power.
Check for the oscilloscope display onscreen.
G
1 You should see the oscilloscope display (see figure 5-2). If not, see the No Display Trouble
Isolation Flowchart.
2 If you see the display, return to the Primary Trouble Isolation Flowchart.
Front Panel Power
Switch
A8 Cursor Keyboard
A7 Front Panel Keyboard
1
1 J3
A6 Scope Interface Board
55
J2
J16
55
A13 Acquisition Board
9
J11
+15 V Bias
A1 Power Supply
W15
3
W16
3
49
W11
49
11
W2
Remote Inhibit
Chapter 5: Troubleshooting
Power Supply Trouble Isolation
5–15