Lincoln Electric IM422 PRO-CUT 40 - Manual (Page 15)

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SYMPTOM CHECK
No LED’s light and the fan does not operate when 1. Check the input power to be sure it is on.
the power switch is turned on. 2. Check the power line fuses and machine
connection.
3. Replace line switch.
No LED’s light when the power switch is turned 1. Disconnect plug P5 from jack J5 at the
on, but the fan operates. auxiliary transformer, T1, and check that
18VAC is present between J5-1 (blue wire)
and J5-2 (blue wire). Replace the trans-
former, T1, if the voltage is not within spec-
ifications. Reconnect plug P5 to jack J5.
2. Check for 15VDC being present between J6-6
(+, lead number 302) and J6-1 (-, lead
number 275D). Replace the POWER BOARD
if voltage is low.
3. Check for 5.5VDC being present between
J2-8 (+, lead number 808) and J2-2 (-, lead
number 802). Replace the MICRO CONTROL
BOARD if voltage is low. Replace the STATUS
BOARD if voltage is OK.
The “MACHINE ON” LED is lit, but there is no 1. Check the air supply to the machine. If the
response when the trigger is pulled. If another air does not flow, the machine will not start.
LED or combination of LED’s are on or blinking, The “AIR PRESSURE” LED must be lit when
refer to the section under that combination. air is flowing.
2. Check for proper TRIGGER SWITCH operation.
There should be continuity between J20-2 and
J20-4 when the trigger switch is depressed and
no continuity when the switch is not depressed.
Replace the trigger switch if defective.
3. Check for greater than 4VDC between J16-2
(+, lead number 502) and J16-1 (-, lead number
501) when the trigger switch is depressed (the
voltage should be 0 otherwise). If the voltage
is not correct, replace the PWM CONTROL
BOARD.
4. Check the operation of the air solenoid by
switching the machine to “PURGE”. If the
pressure is sufficient, the air should begin to
flow and the “AIR PRESSURE” LED should
turn on.
A. If the air does not flow and the “AIR
PRESSURE” LED does not light, check the
following:
1. Check the 115VAC between J5-9 (lead
number 215) and J5-6 (lead number
215A) at the auxiliary transformer, T1.
If voltage is not correct, replace the
transformer, T1.
2. Check for 115VAC between J18-1 (lead
number 215C) and J18-4 (lead number
215A or 215B) at the air solenoid.
a. If there is not 115VAC between J18-1
and J18-4, check for <0.5VDC
between J1-5 (+, lead number 505)
and J1-1, (-, lead number 501).
Replace the PWM CONTROL BOARD
if the voltage is OK, or replace the
MICRO CONTROL BOARD if the volt-
age is high.