P.C. BOARD TROUBLESHOOTING GUIDE
3.LED L3 indicates power is being applied to fault pro- tection relay 2CR, when wire feeder button is pressed or jumper is connected across 2 and 4.
4.LED L4 indicates when fault protection circuit is being activated.
5.LED L5 indicates a control signal is being supplied to the firing circuit. As the output control is varied, LED L5 should change brilliancy.
FIRING CIRCUIT P.C. BOARD
Machine settings | Terminals #2 and #4 jumpered on |
for P.C. board | |
troubleshooting | |
| tion. |
All nine light emitting diodes must be lit when the power source is turned on and the wire feed arc start button is pressed or a jumper is connected between 2 and 4.
1.LED L7 indicates AC power being supplied to P.C. board from control transformer T2. If not lit, check voltage across terminals 203 and 204 on the terminal strip lo- cated on the left side of the bottom fan baffle. Voltage should be approximately 115 volts. If no voltage indi- cates a supply problem, check wiring and transformer. If voltage is present, turn the machine off, remove the
If no voltage and there is voltage at terminals 203 and 204 on terminal strip
2.LED L8 indicates AC power being supplied to P.C. board from control transformer T3. If not, follow the same procedure as above in (1) for terminals 205 and 206 on terminal strip
3.LED L9 indicates AC power being supplied to P.C. board from control transformer T4. If not, follow the same procedure as above in (1) for terminals 207 and 208 on terminal strip
4.LED L1 through L6 indicate gate signals are being sup- plied to the main power SCR’s L1 through L6 respec- tively. If light L5 on the “Control/Fault Protection” circuit P.C. board and lights L7 through L9 on the “Fir- ing” circuit P.C. board are lit and LED’s L1 through L6 are not lit, check lead 231 between the “Firing” P.C. board and the “Control/Fault Protection” P.C. board that is not broken and is connected to each connector. If the lead shows continuity and LED L1 through L6 are not lit, replace the”Firing Circuit” P.C. board. If any one of the LED’s L1 through L6 is not lit and lights L7 through L9 are lit, replace the “Firing Circuit” P.C. board.
If troubleshooting guide indicates a possible P.C. board problem, the guide on page ? can be used to locate the problem.
OUTLINE FOR DC-1500 TROUBLESHOOTING GUIDE
NO WELDER OUTPUT
(INPUT CONTACTOR “ON” TERMINALS 2 AND 4 CLOSED)
CHECK CONTROL BOARD
LED L5
|
|
| IF |
| OFF |
|
| IF |
| ON |
|
|
| |||
|
|
|
|
|
|
|
| |||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
| CHECK |
| LED L1 | CHECK “FIRING” BOARD | |||||||||||
|
|
|
|
|
|
|
|
|
|
| LED’S |
|
|
| ||
IF |
| OFF |
|
|
| IF |
| ON |
|
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
|
| ||||
|
|
|
|
|
|
|
|
|
|
| ALL |
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
| |||||
CHECK AC |
|
|
| REPLACE |
| NINE LIGHTS | ||||||||||
INPUT TO |
|
|
| “CONTROL/ |
|
| SHOULD |
|
|
| ||||||
“CONTROL/ |
|
|
| FAULT |
|
| BE | ON |
|
|
| |||||
FAULT |
|
|
| PROTECTION” |
|
|
|
|
|
|
|
| ||||
PROTECTION” |
|
|
| BOARD | IF YES |
|
|
| ||||||||
BOARD |
|
|
|
|
|
|
|
|
|
|
| IF | NO | |||
POSSIBLE |
|
|
|
|
|
| CHECK GATE |
|
|
| ||||||
|
|
|
|
|
|
|
|
| ||||||||
DEFECTIVE T7 |
|
|
|
|
|
| LEAD | CHECK | ||||||||
TRANSFORMER | CONNECTIONS | LED’S | ||||||||||||||
|
|
|
|
|
|
|
|
| TO SCR’S | L7, L8, L9 | ||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
| IF ONE |
| IF ON AND | ||||
|
|
|
|
|
|
|
|
|
| OR MORE |
| OTHER LIGHTS | ||||
|
|
|
|
|
|
|
|
|
| ARE | OUT |
| ARE | OUT | ||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
| CHECK AC |
| REPLACE | ||||
|
|
|
|
|
|
|
|
|
| INPUT TO |
| FIRING | ||||
|
|
|
|
|
|
|
|
|
| BOARD, |
| BOARD | ||||
|
|
|
|
|
|
|
|
|
|
| ||||||
POSSIBLE
DEFECTIVE TRANSFORMERS T2, T3, OR T4
MACHINE HAS OUTPUT BUT | ERRATIC |
| WELDING | |
TRIPS OFF | IMMEDIATELY | CHECK |
| PROCEDURE |
|
|
| ||
CHECK FOR SHORT |
|
|
| |
|
|
| ||
BETWEEN ELECTRODE AND | CHECK MODE SWITCH FOR | |||
WORK LEADS, REMOVE | PROPER POSITION FOR | |||
EXTERNAL LEADS FROM | PROCESS |
| BEING USED | |
THE OUTPUT | TERMINALS |
|
|
|
|
| CHECK LED’S | ||
IF TROUBLE STILL | L4, L5, L6 | |||
PERSISTS, | FOR EQUAL | |||
CHECK LED L3 ON | BRILLIANCY | |||
“CONTROL/FAULT |
|
|
| |
PROTECTION” | BOARD | IF LIGHTS ARE NOT ALL | ||
|
| APPROXIMATELY EQUAL | ||
IF LIGHT GOES ON,THEN | BRIGHT, REPLACE | |||
QUICKLY OUT WHEN START | FIRING P.C. BOARD | |||
BUTTON IS PRESSED, |
|
|
| |
“CONTROL/FAULT |
|
|
| |
PROTECTION” BOARD IS |
|
|
| |
DEFECTIVE AND SHOULD |
|
|
| |
BE REPLACED |
|
|
| |
| WARNING | |
| • Have an electrician install and | |
| service this equipment. | |
| • Turn the input power off at the | |
| fuse box before working on | |
| equipment. | |
| • Do not touch electrically hot parts. | |
ELECTRIC SHOCK | ||
| ||
can kill. |
|