DSO 4102C seems starting but display is black. I need electrical circuit. - Electronic Engineer Discuss

Hello, to All Members! I am Sergiy from Ukraine. Would you be so kind to help me? My Hantek DSO 4102C after the 1st year of working "unexpectedly died". Once, after starting, LCD became black. All buttons are working and LEDs are working too. I checked power supply. All are good: +14,5V; +12V; -8V; +6,4V; +5V;+3,3V. I found control points on the main board (DSO4000C V1.02 2015-03) & checked them. They are: +14,4V; +12V;-7V; +5V; -5V; +3,3V; +2,5V; +1,8V; +1,3V; +1,25V. Only +2,5V was absent at all. One SMD SOT23 part smd marked as (SANE) was damaged (burned). Now I know that it is the 4.096V precision voltage reference. I did not find the electrical circuit of HantekDSO 4102C. After installing a new REF3040 (4.096V precisionvoltage reference ), i got +2,5V, but the display still does not work. Buttons are working and the buzzer too. I can hear beeps after the plugging in USB flash drive or SD card. I did NOT found official Hantek service in Ukraine. Can someone help me with a Hantek DSO 4102C service manual or electrical circuit diagram?