Thermal Dynamics CUTMASTER 81, Service Manual

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Manual 0-2957 4-7 TROUBLESHOOTING
11. Faulty ON/OFF switch
Measure for 28 VAC on the Main PC Board be-
tween J18-5 to J18-6.
a. If voltage is not present replace the ON/OFF
Switch.
12. Faulty Main PC Board
Measure for 12 vdc on Main PC Board from TP4 to
TP1.
a. If voltage is not present, replace the Main PC
Board.
D. Fans do not run; AC , GAS and TEMP
indicators ON, DC indicator off
A
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t # A-03
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84
1. Air flow through unit is restricted
a. Provide adequate air flow
2. Exceeded Duty Cycle of Power Supply
a. Deactivate torch and wait for fan to cool unit. Refer
to Specifications Section for proper duty Cycle for
this unit.
3. Faulty Fan(s)
Measure for 230 VAC (±) on the Main PC Board
from J15-1 to J15-5, and from J15-2 to J15-6.
• If voltage at J15-1 to J15-5 is correct, replace lower
Fan (M1).
• If voltage at J15-2 to J15-6 is correct, replace up-
per Fan (M2).
4. Faulty Temperature Sensor / Switch
a. Shut input power off. Check IGBT Heatsink
Temp Sensor (TS1). Disconnect wire connector
P29 from terminal J29 on Main PC Board. Check
connector pins 1 and 2 for 10K ohm (±25%) (at
ambient temperature). If resistance is not 10K
ohm (±25%), replace TS1.
b. Shut input power off. Check Inductor Temp
Switch (TS2). Disconnect wire connector P32
from terminal J32 on Main PC Board. Check
connector pins 1 and 2 for resistance. If resis-
tance is greater than 12K ohms, replace output
inductor (L1). If temp switch is open, replace
Main PC Board.
E. No gas flow; RUN / RAPID AUTO RESTART /SET
switch in SET position; AC indicator ON;
TEMP GAS and DC indicators OFF
A
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t # A-03
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85
1. Gas supply not connected to unit
a. Connect to gas supply.
2. Gas supply not turned on
a. Turn gas supply on.
3. Gas pressure too low
a. Adjust gas pressure per pressure setting label
on power supply.
4. Faulty RUN / RAPID AUTO RESTART / SET switch
a. Check continuity.
5. Faulty Gas Solenoid circuit
a. Test Gas Solenoid circuit per Subsection 4.10-E;
repair as necessary.
6. Faulty Logic Board
a. Replace logic board.