Check Procedure References
Refer to the corresponding check procedure. Each check procedure is numbered the same as in
Figure 4-8 for quick reference.
Check 1, DC-DC Converter Output Voltage
1. Remove the cover referring to \Cover Removal" in Chapter 3.
2. Turn on the 4339B.
3. Using a multimeter, check to see if the voltages between the test pads (TPs), shown in
Figure 4-9, on A1 Main Board Assembly are in the ranges listed in Table 4-1.
4. If passed, proceed to \Check 2, LCD Displays Anything?", otherwise proceed to \Check 10,
Fuse and Line Switch".
Table 4-1. DC-DC Converter Output Voltages (Connected)
4-12
T roubleshooting
Figure 4-9. DC-DC Converter Output Voltage Check
Test Pad (+) Test Pad ( )
9 (\+5")
7 (\+12")
6 (\ 12")
Range
6
8 (\GND") 5.1
0.2 V
6
5 (\COM")
12
0.6 V
6
5 (\COM")
12
0.6 V