Fault finding as per Stuart Dorling




Is the power lamp on in the top left hand corner of timer


Check that the voltage is 380V / 400V not 220V



Check incoming power, check main switch is on, check fuses on connecter board (2Amp 5 x 20 Glass Fuse)

Does the screen display


Does it give an error message



Check above or replace timer & switch off then on again.

Does the screen display an error message


Confirm what it is e.g.: Thermo, Hi Lift or ■■■■

Display Thermo


Check Temp of Transformer & Thyristor. If Cool check wires for continuity (NB Machine must be off when doing this test)

Display Hi-Lift


Press HI-Lift or retract button to close tips to working stroke.



Check Wire bridge from +24 to Hi-Lift Connection.

Display ■■■■ & SS


Timer Faulty - Replace

On Foot Pedal Machines


Check Tip Distance and operation of rear limit switch.

Weld On/Off Switch


Welding will take place



Tips close but no Weld

On Air Operated Machines


Check Air Pressure

Air Pressure


Check Supply



Check regulator setting (must be higher than 2.5Bar)

Welding Tips


Check that tips touch and that there is over travel (Bite). Check for thread seal tape on tapers of tips, or excess dirt on tips.



If screw adaptors are used, check that the thread seal tape is only used on half the thread.




Squeeze Time


The Pre SQ and SQ time together must be long enough that the tips have time to close and build pressure before the weld take place.

Weld Time


This time is set so that there is enough time for the weld to take place and fuse the parts together, generally the outer blue ring width should be half the weld nugget size.



Set the heat to achieve a good weld on the shortest weld time without excessive weld spatter.



Time for the weld to cool before the tips separate, generally if the centre of the weld is blue hold time is too short, centre should be shiny.

Off Time


This is set for the timer to be in repeat mode, meaning that the spot welder will close - weld - open - close - weld - open until ones foot is removed.