DMR-E85H works fine after replacing IC but ......

Quite many possibilities. Since you replaced the IC, I'd figure you have a little understanding of electronics and ESD procedures. You now need to troubleshoot the driver for the display. Do a little research with your DVM... make sure the display is getting V. Should the unit be a uP type system, you are probably looking at the uP display driver circuitry [all in one] being bad and no way around the replacement should you desire a display. Should the unit be slightly older, you may get lucky with finding a cap or transistor problem for the driver. Moreso trans than cap.

Wish it were here.. always easier to take a peak and find the problem when it is in front of me.