Thermal Arc 185 AC, Service Manual

Page: 63 / 122

10-13
ARCMASTER 185 ACDC 200 ACDC
May 22, 2006
6) Verify bus voltage (the voltage of the electrolytic
capacitor after rectification) using a DC voltmeter.
(The capability of the voltmeter should be more
than 1000VDC.) Using a DC voltmeter, measure
between the points TB1 (P) [+] and TB2 (N) [-]
on PCB1 (WK-5477). Points TB1 (P) and TB2 (N)
can be found on the parts side of PCB1. See Figure
11-9. The measured voltage should be
approximately 1.4 times larger than input voltage
measured in #1 above. Replace diode D1 if the
calculated measurement is not within the
corresponding range (260 ~ 360 / 580 ~ 720 VDC)
following the process in section 11.3.31.
PCB1
TB1
TB2
Figure 10-9: The check points TB1(P) and TB2(N)
7) After the replacement of D1, if the above voltage
is still abnormal, replace PCB1 (WK-5477).
10.07 Verification of Power Supply
Voltage
CAUTION
Before performing any portion of the
procedure below, make certain the unit is
placed in the initial set up condition as
described in section 10.05 "Preparation".
1) Verify Power Supply voltage using an DC
voltmeter. (The capability of the voltmeter should
be more than 50VDC.) Operate at all input voltages
as noted on the nameplate on the rear panel when
testing the power supply.
2) On the PCB3 (WK-5548) and PCB6 (WK- 5549),
measure the voltages according to the following
table. The check points and the reference are
obtainable on the top side of PCB6 (WK-5549).
The locations of points are indicated in Figure 11-
10, 11-11.
TP1
TP2
TP3
TP0
PCB6
Figure 10-10: Checkpoints TP0-TP3 on PCB6
Check Point
PCB6
Reference
PCB6
ACCEPTABLE
VALUE
TP1 TP0 +5VDC
TP2 TP0 +15VDC
TP3 TP0 –15VDC
Table 10-1: Checkpoints TP0-TP3 on PCB6