Circuit Fault Isolation - Thermal Dynamics CE PAK Master 150XL Service Manual

Subsection 4.09 includes specific test procedures and LED
status identification tables. The subsection is referenced
by the troubleshooting guide for the specific test to be
performed.
The troubleshooting guide has six subsections as follows:
Section 4.06 - Circuit Fault Isolation
Section 4.07 - Main Input and Internal Power Prob-
lems
Section 4.08 - Pilot Arc Problems
Section 4.09 - Main Arc Problems
Section 4.10 - Test Procedures
C. How to Use the Troubleshooting Guide
The following information is a guide to help the Service
Technician determine the most likely causes for various
symptoms. This guide is set up in the following manner:
1. Perform operational check(s) on the equipment to iso-
late problem to possible circuit(s) per Section 4.06,
Circuit Fault Isolation. Refer to the Appendix Pages
for PC Board layouts, as necessary.
2. Determine symptom and isolate to defective assem-
bly using the following format:
X. Symptom (Bold Type)
Any Special Instructions (Text Type)
1. Cause (Italic Type)
a. Check/Remedy (Text Type)
a. Locate your symptom in the appropriate sub-sec-
tion.
b. Check the causes (easiest listed first) for the symp-
tom.
c. Check the remedies listed for each cause.
3. Repair as needed being sure to verify that unit is fully
operational after any repairs.
NOTES
Many signals are transferred between Printed Cir-
cuit Board Assemblies on Ribbon Cables. If these
cables become faulty they can then cause various
problems. Do not forget about these cables when
troubleshooting.
While troubleshooting visually inspect the inter-
nal components for signs of overheating, fractures
and damage.
SERVICE TROUBLESHOOTING

4.06 Circuit Fault Isolation

This section is used before troubleshooting to help iso-
late the defective circuit, identify symptoms, and test the
unit for proper operation.
Follow all instructions as listed and complete each
in the order presented.
Follow the instructions as given to identify the possible
symptom(s) and the defective circuit. After repairs are
complete then run the following tests again to verify that
the unit is fully operational.
A. Initial Setup Conditions
Connect gas supply to rear of Power Supply.
Turn on gas supply and adjust the Plasma Gas Regulator
to 65 psi (4.5 bar) and the Secondary Gas Regulator to 60
psi (4.1 bar).
Set the Power Supply controls as follows:
ON/OFF switch to OFF
RUN/SET switch to SET
CURRENT control potentiometer to maximum
STANDARD/LATCH switch to STANDARD (See
NOTE)
STANDARD/LATCH Switch was not installed on
revision AU or earlier Power Supplies.
B. Main Input and Internal Power Tests
Connect main AC power to the unit.
Set the Power Supply ON/OFF switch to ON and note
the following:
• AC indicator blinks for eight (8) seconds, then steady
ON
• Main Contactor energizes (clicks once) while AC In-
dicator is blinking
• Inrush Relay energizes (clicks once) after AC Indi-
cator stops blinking
• TEMP Indicator OFF
• GAS Indicator ON
• Gas flows
• Fans operate
• DC Indicator OFF
4-6
NOTE
NOTE
Manual 0-2728