Tweco 130i Transarc Service Manual - Manual (Page 45)

TRANSARC 130i
Manual 0-5282 6-3 TROUBLESHOOTING
6.03 Advanced Troubleshooting
If the problem cannot be solved by the basic (external) troubleshooting guide, the Power Source cover will have
to be removed to allow the technician to analyze failures with a few common tools.
!
WARNING
Turn off power and disconnect mains supply plug from receptacle before working on the unit. Allow
two minutes for capacitors to discharge after disconnection from mains supply voltage.
Checking Unit Before Applying Power
!
!
Turn SW1 to OFF position, and disconnect unit from primary line voltage before working on unit.
!
Significant DC voltage can remain on capacitors after unit is Off. Wait until all front panel LED’s are off
before removing case.
!
Check DC bus voltage according to Section 6.09 after removing case.
!
Before troubleshooting or applying power to unit, complete the following checks to avoid causing further
damage.
6.04 Test Equipment and Tools
• Digital Multimeter
• DC clip-on ammeter
• Screwdriver and spanner
• CRO (20 Mhz bandwidth) & isolating transformer
6.05 Visually Inspect
Visually inspect the inside of the Power Source. The levels of current present in these units can cause burning or
arcing of PCB, transformers, switches, or rectifier when a failure occurs. Carefully inspect all components within
these units.
Look in particular for the following:
a) Loose or broken wires or connectors.
b) Burned or scorched parts or wires or evidence of arcing.
c) Any accumulation of metal dust or filings that may have caused shorting or arcing.
If any parts are damaged, they must be replaced. Refer to the Spare Parts section for a complete list of components
used in the Power Source.
Locate the faulty component(s) then replace where necessary.