52 - "Trg" On Display (O). In Mig And Tig Mode, Start Button Pressed Upon Start-Up; 53 - "Trg" On Display (O). Start Button Pressed While Resetting From Stop Due To Temperature Outside Limits; 54 - Short-Circuit Between Torch And Workpiece Upon Start-Up; 56 - Short-Circuit At The Output Lasts Too Long - Cebora SOUND MIG 3840/T Pulse Service Manual

CEBORA S.p.A.
board (232). Correct value = junction of one diode in one sense and 1 Kohm with
the probe terminals reversed. If incorrect, replace the motor control board (232).
♦ With power source off, temporarily disconnect the flat cable from J7 on motor
control board (232) and power up the power source again. Make sure that on
terminals 9(+) and 11(-) of the patch connector disconnected from J7, the voltage
= approximately +5 Vdc, and on terminals 12(+) and 11(-) of the patch connector
disconnected from J7, voltage = approximately +5 Vdc. If incorrect replace the
connector board (225).
♦ Regular serial line power supply.
3.7.14 - 52 - "trG" on display (O). In MIG and TIG mode, start button pressed upon start-
up.
See START COMMAND TEST and START SIGNAL TEST, par. 3.5.4.
3.7.15 - 53 - "trG" on display (O). Start button pressed while resetting from stop due to
temperature outside limits.
The high temperature alarm stops the power source, lights the yellow led (G) and signals the
corresponding alarm to the overheated unit (see alarms 73 and 74) on the control panel (parr.
3.7.20 and 3.7.21). These alarms are automatically reset when the temperature returns within the
allowed limits.
It may occur that the unit resets when the start command is present; therefore, to prevent the
power source from starting suddenly due to a random reset, this situation is detected and causes a
power source block, with the message "trG" on display (O).
To restore proper operation, remove the start command, performing the START COMMAND
TEST and START SIGNAL TEST par. 3.5.4, if necessary.

3.7.16 - 54 - Short-circuit between torch and workpiece upon start-up.

Upon power source start-up this test checks the operating conditions by performing a brief
test to generate the open-circuit output voltage. While this is taking place it is important that the
torch not touch the workpiece or welding bench.
The following conditions may be detected during this test:
− Output voltage present and output current present = error 54;
− Output voltage present and output current absent = correct operation;
− Output voltage absent and output current present = error 54;
− Output voltage absent and output current absent = error 10.
Error 54 indicates a possible short-circuit or isolation leak in the power circuit downstream of
the diode group (567) and choke (530).
Check the wiring between connector J1 of micro board (543) and current transducer (529),
and the power wiring between the "cathode" terminals of diode group (567) and the output
terminal (+)(BR) of the power source, and between the transformer (531) central socket, choke
(530) and output terminal (-)(BO) of the power source.
If you find defective connections, fix and replace any damaged components.
Carry out the CURRENT TRANSDUCER (529) POWER SUPPLY TEST and POWER
SOURCE OUTPUT CURRENT FEEDBACK SIGNAL TEST in par. 3.5.9.
Replace the control board (543) and/or current transducer (529).

3.7.17 - 56 - Short-circuit at the output lasts too long.

It is normal to detect short-circuits at the output during welding, as long as they do not last
beyond a given interval. "Error 56" indicates that the short-circuit has exceeded this limit.
This situation may be caused by a short-circuit created between the contact tip and gas nozzle
on the MIG torch due to deposits of dirt or metal dust.
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