between the second conveyor belt 124 and the second side board 122 the second working platform 123 is used to hold testing devices not shown the second support legs 125 are fastened to a periphery of the second working platform 123 used to support the testing line 12 the height of the second support legs 125 is less than the height of the first support legs 115 the second top board 121 includes a lamp 1211 used to provide light to the testing line 12 the second side board 122 includes a material platform 1221 protruding therefrom towards the second conveyor belt 124 used to hold testing materials the second top board 121 the second side board 122 and the second working platform 123 partially enclose a testing space 136 the testing space 136 is for an operator to conduct testing on electronic components e g to judge whether an lcd for any visual defects referring to fig4 the packing line 13 includes a third top board 131 a third side board 132 a third working platform 133 a third conveyor belt 134 and a plurality of third support legs 135 the third top board 131 and the third working platform 133 are respectively mounted to the third side board 132 the third conveyor belt 134 is located between the third working platform 133 and the third side board 132 the third working platform 133 includes an.