output voltage fluctiation

Hello, I made a device where I am using Texas Instruments LM2700 boost converter (2.7-4.2V to fixed 5V output, or in other words 18650 battery to 5V.) I have already made the PCB (according to the datasheet example) and assembled all the components. However, I face a really strange output...

The outputs of the FIMER 201 welding machine give 0 Volts and a clicking sound is heard from the control circuit and the yellow and green light lamps are constantly flashing. The Output Voltage is fluctiating. Why is the machine giving this error? What should be done to fix this fault? Which...