Thermal Dynamics (a Thermadyne Company) Merlin 3000 - Manual (Page 25)

Manual 0-2533 21 SERVICE TROUBLESHOOTING
3. Gas Control (GC3000) on wrong setting
a. Select input that has gas connected.
4. Gas supply turned off (or tank empty)
a. Check gas supply
5. Faulty solenoid valve:
SOL1 - plasma gas,
SOL2 - secondary gas,
SOL3 - secondary water,
SOL4 through SOL9 - Optional Gas Select
a. Check solenoid for sticking or clogging. Check
coil resistance per the following:
SOL1 and SOL3 should be approximately 400
ohms)
SOL2 should be approximately 100 ohms)
SOL4 through SOL9 should be approximately
300 ohms)
6. Faulty switch (SW3-A) or Gas Control (GC3000) Sec-
ondary Select Switch
a. Check SW3-A for continuity (wire #75 to #88
for secondary gas, #75 to #89 for secondary wa-
ter)
7. Faulty Logic PC Board
a. Refer to Section 4.05-H, Gas Solenoid Circuits.
Replace Logic PC Board if necessary
8. Input gas pressure set too high, preventing solenoids
from operating
a. Remove input gas line and retry
b. Regulate input gas pressure between 90 to 110
psi (6.2 to 7.6 bar)
J. COOLANT indicator off
1. Little or no pressure shown on gauge
a. Check coolant level
b. Check motor rotation and rpm.
c. Check and replace pump if necessary
2. Clogged internal or external coolant filters
a. Check internal and external coolant filters.
Clean or replace if necessary. Flush the old cool-
ant from the system (see note below).
NOTE
With a clogged internal coolant filter or Torch and
leads the Coolant Pressure Gauge will be normal,
but the Pressure LED, indicates flow, will be OFF.
3. Clogged torch or leads
a. Check torch and leads and replace if necessary.
Flush the old coolant from the system (see note
above).
4. Faulty flow switch (FS1)
a. Check and replace flow switch if necessary
5. Faulty Logic PC Board
a. Refer to Section 4.05-I, Coolant Flow Sensor
Circuit Check. Replace Logic PC Board if nec-
essary.
6. Faulty LED/current control board
a. Refer to Section 4.05-I, Coolant Flow Sensor Cir-
cuit Check. Replace Logic PC Board if neces-
sary.
K. Coolant conductivity indicator off
1. Ionized or contaminated coolant
a. Check coolant conductivity and deionizer car-
tridge. Replace both if necessary
2. Faulty (or contaminated) conductivity probe
a. Clean conductivity probe and replace if neces-
sary
3. Faulty Logic PC Board
a. Refer to Section 4.05-J, Coolant Conductivity
Circuit. Replace Logic PC Board if necessary.
4. Faulty LED/Current Control PC Board
a. Refer to Section 4.05-J, Coolant Conductivity
Circuit. Replace LED/Current Control PC
Board if necessary
L. Press cutting machine START and nothing hap-
pens or standoff finds height then nothing
happens (no gas flow or pilot)
1. Start signal not getting to the Power Supply or Power
Supply is defective.
a. Determine if Remote Control or Power Supply
is at fault. Remove Remote Control or CNC
cable from J15 (or TB2). Jumper TB2-1 & 2 to
enable unit, then jumper TB2-3 & 4 for START.
If the pilot starts, after preflow, Remote Con-
trol or CNC is faulty. Refer to Section 4.05-L,
Remote Control Start Circuit. If no pilot, refer
to Section 4.05-K for Power Supply Start Cir-
cuit.