CIGWELD TRANSTIG 300 AC/DC, Service Manual, Page: 75 / 134

1
3
ADVANCED TROUBLESHOOTING
13.
5.6 Verification of the secondary
Diode (D2-D7)
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 the characteristic of the secondary
diode, D2-D7, using a diode tester.
2 ) Refer to Table 11-6 and Figure 11-15 for
the checkpoints on D2-D7.
Table 1
3
-6: Tester checkpoints in D2-D7
Figure 1
3
-15: Tester checkpoints in D2-D7
13.
5.7 Verification of the primary
IGBT (Q1-Q24)
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) Check whether there are any abnormalities on
the appearance of PCB8-PCB11.
2) Verify the characteristic of the primary IGBT
(Q1-Q24), using a diode tester.
3) Refer below Table 11-7 and Figure 11-16 for
the checkpoints on PCB8-PCB11.
Table 1
3
-7: Tester checkpoints in the Q1-Q24
Figure 1
3
-16: Tester checkpoints in the Q1-Q24
COMPONENT
TESTED
TERMINALS
ACCEPTABLE
VALUE
Positive
lead
Negative
lead
Diode 1 of
D2-D7
Anode
Cathode
Cathode
Anode
0.2 to 0.3V
Open
Diode 2 of
D2-D7
Anode
Cathode
Cathode
Anode
0.2 to 0.3V
Open
Anode
Diode 1 Diode 2
Anode
Cathode Cathode
D2
D3
D4
D7
D6
D5
COMPONENT
TESTED
TERMINALS
ACCEPTABLE
VALUE
Positive
lead
Negative
lead
Collector-Emitter
of Q1
a Q12 with
PCB8 and PCB9
C
CE
CE
C
Open
0.2 to 0.5V
Collector-Emitter
of Q13
a Q24 with
PCB10 and PCB11
CE
E
E
CE
Open
0.2 to 0.5V
TRO_0031
C CE E
TRO_0031
C CE E
PCB10
PCB11
PCB8
PCB9
C CE E
June 30, 2008 13-15
SERVICE MANUAL TRANSTIG 300 AC/DC