Epson LQ-860 Technical Manual page 200

REV.-A
5.3.1
The power supply circuit (MONPS/MONPSE board) is divided into three blocks: (1) Input filter circuit, (2)
Secondary side, and (3) Main switching circuit.
AC
I N
Figure
If trouble occurs, first determine the faulty block and then find the bad component, referring to Table 5-7
and Figure 5-6.
1. Since this power supply is an isoloated switching regulator, do not use a grounded measuring
instrument such as a multimeter or oscilloscope. If a grounded instrument is used, fuse F1 may
burn out. Be sure that the measuring instrument is not connected to ground before using it on this
power supply circuit. In most cases, the line plug shown in Figure 5-5 will avoid this problem.
NOTE: For Japan
Figure 5-5. AC Connector for Measuring Instruments
2. Measure the resistance values on the circuit board after
Board Unit Repair
I
5-4.
DANGER
5-14
Board Block Separation
turn the power off.
+ 35 v
.-",
'