CIGWELD TRANSTIG 300 AC/DC, Service Manual, Page: 73 / 134

1
3
ADVANCED TROUBLESHOOTING
3) If any of these voltages are not present or
are below a 10% tolerance, replace the
PCB3 (WK-5548). Refer to section 1
4
.3.3.
13.
5.3 Verification of the Cooling
Fan, FAN1, Drive Circuitry
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 condition of the cooling fan, FAN1,
using a DC voltmeter. (The capability of the
voltmeter should be more than 50VDC.) Using
a DC voltmeter, measure between PIN 1 (Posi-
tive [+]) and PIN 2 (Negative [-]) of CN11 on
PCB3 (WK-5548). The location of connector
CN11 of PCB3 is indicated in Figure 11-12.
When you measure the above voltage, do not
remove the connector. Conduct the measure-
ment while the connector plug and receptacle
are still connected.
Figure 1
3
-12: Verification of the FAN1
2) Using the measurement taken above, follow
the chart below for possible failure modes.
Table 1
3
-3: Verification of the FAN1
At the time of a low output and standby, as
for this equipment, rotation of a fan becomes
slow. Therefore, exact voltage measuring
becomes impossible. Perform the check of
voltage in the state of abnormalities.
When verifying the voltage, confirm that the
AC input voltage remain within the operating
range of the unit. (The AC input does not
drop below 180VAC).
PCB3
CN11
pin1
pin2
FAN1
Status
Voltage
measurement.
(1PIN-2PIN of
CN11 on PCB3)
Remedy
Case 1 Rotating DC 18 a
25V
FAN1 drive circuit
is normal.
Case 2 Rotating Below DC 18V
Replace PCB3.
Refer to section
1
4
.3.3.
Case 3 Inactive Below DC 18V
Replace PCB3.
Refer to section
1
4
.3.3.
p
Perform
"2. Verification of
the Power Supply
Voltage".
Refer to section
1
3
.5.2.
Case 4 Inactive DC 18 a 25V
Replace the FAN1.
Refer to section
1
4
.3.24.
June 30, 2008 13-13
SERVICE MANUAL TRANSTIG 300 AC/DC