Tweco 81 with SL100SV - Manual (Page 75)

Manual 0-4641 5-11 SERVICE
5
5.04 Advanced Troubleshooting Guide - General Information
WARNING
There are extremely dangerous voltage and power levels present inside this unit. Do not attempt to diagnose or
repair unless you have had training in power electronics measurement and troubleshooting techniques.
A. General Information
This Section covers advanced troubleshooting, which requires power supply disassembly and live measurements. Advanced
troubleshooting and repair of this unit is a process which should be undertaken only by those familiar with high voltage high
power electronic equipment.
If major complex subassemblies are faulty, the faulty subassembly must be returned for repair. Refer to Repairs & Replacement
Procedures, for parts replacement instructions. Replacement instructions for some parts are included in this manual. Replace-
ment instructions for parts not covered in this manual are included with the replacement part.
Under no circumstances are field repairs to be attempted on Printed Circuit Boards or other subassemblies of this unit. Evidence
of unauthorized repairs will void the factory warranty.
NOTE
Follow all instructions as listed and complete each in the order presented.
B. 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 isolate problem to possible circuit(s) per Subsection 5.06, Circuit Fault
Isolation.
2. Determine symptom and isolate to defective assembly using the following format:
X. Symptom (Bold Type)
Any Special Instructions (Text Type)
1. Cause (Italic Type)
a. Check/Remedy (Text Type)
3. Locate your symptom in the appropriate Subsection.
4. Check the causes (easiest listed first) for the symptom.
5. Check the remedies listed for each cause.
6. Repair as needed being sure to verify that unit is fully operational after any repairs.
NOTES
Many signals are transferred between Printed Circuit Board Assemblies on 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 internal components for signs of overheating, fractures and damage.