CIGWELD TRANSTIG 300 AC/DC, Service Manual, Page: 72 / 134

1
3
ADVANCED TROUBLESHOOTING
6 ) Verify bus voltage (the voltage of the electro-
lytic capacitor after rectification) using a DC
voltmeter. The capability of the DVM
should be more than 1000VDC. Measure
between
the output studs C and E
on PCB8 (WK5479), PCB9 (WK-5479),
PCB10 (WK5479) and PCB11 (WK5479).
The measured voltage should be approximately
1.4 times larger than the input voltage
measured in step 1 (above), except when running
at 460V where the bus voltage will be shared
across all boards, ie each board receiving 0.7
Replace diode D1 if the calculated measurement
times the input voltage measured in step 1 (above).
?
360 / 580
?
is not within the corresponding range
Figure 1
3
-9: The check points TB1(P) and TB4(N)
7 ) After the replacement of D1, if the above volt-
age is still abnormal, replace PCB1
(WK-5493).
13.
5.2 Verification of the 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 1
3
.4.1
"Preparation".
1 ) Verify Power Supply voltage using an DC volt-
meter. (The capability of the voltmeter should
be more than 50VDC.) Operate at all input volt-
ages 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 refer-
ence are obtainable on the solder side of
PCB6 (WK-5549). The locations of points are
indicated in Figure 11-10, 11-11.
Figure 1
3
-10: Checkpoints TP0-TP3 on PCB6
Table 1
3
-1: Checkpoints TP0-TP3 on PCB6
Figure 1
3
-11: Checkpoints CN18 on PCB3
Table 1
3
-2: Checkpoints CN18 on PCB3
TB4(N) TB1(P)
PCB2
Check Point
PCB6
Reference
PCB6
ACCEPTABLE
VALUE
TP1 TP0 +5VDC
TP2 TP0 +15VDC
TP3 TP0 -15VDC
Check Point
PCB3
Reference
PCB3
ACCEPTABLE
VALUE
Pin1 on CN18 Pin3 on CN18 +24VDC
TP3
TP0
TP1
TP2
PCB6
pin 1
pin3
PCB3
CN18
(260~360/580~720VDC). Follow the process in
section 1
4
.3.31.
13-12 June 30, 2008
TRANSTIG 300 AC/DC SERVICE MANUAL