The ssd1315 OLED is display issue?

Hello,
The oled display is sometimes its not showing the data on it, after sometime if we power on and off then its displaying data on it, why this will hanppen ?
vcc = 3.3V, and SDA, SCL with 4.7k pull ups. I am able to see the data on SDA SCL but not on OLED display.
please help me to solve the issue .

Thanks and regards
MOUNIKA