Solution:

Some of TFT LCD does not stable to show up every booting,such as Sharp LQ 14D412. . This may be related to the power on sequecne that is critical to the LCD. There are one register on CHIPS 65550 can be used to change the power sequence. FR04 is the panel power sequenceing delay register. Bit 7-4 is the power up delay the value can be programmmed to 54 ms in incerment of 3.4 milliseconds A value of 0 is undefined. Bit 3-0 is the power down delay . This valuse can be programmed up to 459 mS in incdrment of 29 mS. A value of 0 is undefined. The value depends on the LCD's specs. As an exampel the value for LQ 14D412 works fine with Value of 88.