Firepower, a Thermadyne Company FIREPOWER FP-82 - Manual (Page 25)

Manual 0-2871 4-7 SERVICE
J15 Fuse
INPUT
DIODE
Main PC Board
J15-1
J15-2
J15-5
J15-6
A-03172
Auxiliary
Transformer
E. No gas flow; AC indicator ON; TEMP indicator
OFF; GAS and DC indicators OFF
1. RUN/SET switch in RUN (up) position
a. Switch to SET (down) position.
2. Gas supply not connected to unit
a. Connect to gas supply.
3. Gas supply not turned on
a. Turn gas supply on.
4. Faulty RUN/SET switch
a. Check continuity.
5. Faulty Gas Solenoid circuit
a. Test Gas Solenoid circuit per Subsection
4.10-E; repair as necessary.
F. Gas flows; AC indicator ON; GAS indicator OFF;
DC indicator OFF
1. Gas pressure too low
a. Refer to Torch Instruction Manual for operat-
ing pressures.
2. Faulty Pressure Switch
Measure for 12 vdc from wire #10 to wire #11 at
the Gas Pressure Switch, located on the right side
of the unit. Refer to Appendix 14/15, System Sche-
matic.
a. If 12 vdc is present and pressure is above 50 psi
(3.4 bar), replace Gas Pressure Switch/Solenoid
Assembly. Refer to Section 5.08-A.
b. If pressure is above 50 psi (3.4 bar) and 12 vdc
is not present, replace the Logic PC Board.
3. Faulty Wiring or Faulty Logic PC Board
Check for 12 vdc at Main PC Board pin J24-3 to
J24-4 from
the Logic PC Board. Refer to Appen-
dix 4, Main PC Board Layout.
• If less than a volt, replace Logic PC Board.
J23-1
J23-3
A-03171
Main PC Board
J18-5
J18-6
J24-3
J24-4
J18-3
J18-4
G. Gas continues to flow with RUN/SET switch in
RUN position.
1. Damaged gas solenoid.
a. Turn the front panel ON/OFF switch to OFF.
• If gas continues to flow, debris from the air line
is preventing the solenoid from closing. Clean
or replace the solenoid.
2. Faulty RUN/SET switch.
a. Check continuity.
3. Faulty Logic PCB.
a. Measure for approximately 12 vdc between
P1-7 and TP-1 on the Logic PCB.
• If 12 vdc is present, replace Logic PCB.
• If less than 2 vdc, replace Main PCB.
H. Arc in torch without activating torch; Gas flows;
AC indicator ON; GAS and DC indicators ON
1. Faulty torch switch
a. Refer to appropriate Torch Instruction Manual
and check continuity.
2. Faulty torch leads
a. Refer to appropriate Torch Instruction Manual
and check continuity.
3. Faulty Power Output PC Board (Refer to Appendix
11, Power Output PC Board Diagram)
a. Disconnect J41 Connector from the Power Out-
put PC Board.
b. Unplug Logic PC Board.