Hantek DSO4072s's AWG (generator) option not working installed originally

[handsome]

Hi. I bougth Hantek DSO4072s oscilloscope 4 years before. It has AWG (wave form generator) option installed originally. Recently AWG option was broken. Oscilloscope working normal but Output of generator give only about 8 mV dirty square wave whichever wave form I choose. I changed DAC902E but result is the same. I tried to find problem, finally saw there isn't no clock signal at CLK input pin (28th pin of DAC902E) which coming from FPGA. I think the problem software related. I need your help. Thanks.