Section TOC
Master TOC
TROUBLESHOOTING & REPAIR |
POWER BOARD TEST
Test D: Test for 0.2 VDC to 0.3 VDC Gate Drive Voltages to the SCR Module.
NOTE: This test requires that the torch trigger be pulled to activate the circuit. Be sure to use an isolated meter because of the high voltage and high frequency produced.
NOTE: This test requires testing DC voltages. Polarity must be observed.
1.Locate and insert probes into the following Power Board plug locations (See Figure F.11):
a.Insert the NEGATIVE probe into Plug 1J21 (lead #383
b.Insert the POSITIVE probe into Plug 3J20 (lead G2 +) lead cavity.
2.Turn the ON/OFF Power Switch to ON.
3.Pull torch trigger. When air pre- flow times out and the pilot arc is established, 0.2 VDC to 0.3 VDC should be present.
4.Release torch trigger.
5.Locate and insert probes into the following Power Board plug locations (See Figure F.11):
a.Insert the NEGATIVE probe into Plug 1J21 (lead #383
b. Insert the POSITIVE probe into Plug 4J20 (lead G1 +) lead cavity.
2.Turn the ON/OFF Power Switch to ON.
3.Pull torch trigger. When air pre- flow times out and the pilot arc is established, 0.2 VDC to 0.3 VDC should be present.
4.Release torch trigger. Turn ON/OFF Power Switch to OFF.
a.If specific voltages ARE NOT present, check Power Board Plugs J20 and J21 and Control Board Plug J6 for loose or faulty wiring.
b.If no loose or faulty wiring is found, the Power Board, Control Board, or SCR module could be faulty. Replace.
