Today I used some thermal grease on the surface of both GPU and CPU of Pi3a Pi 3 to reduce the heat by the use of heat-sinks. A little of the thermal grease has gone below the GPU.
After that, sometimes when I power-on the board, only red LED is on and the green LED is off and sometimes It starts well and boot the OS and after that the display will go dark!
Do you think I broke the board? What do you suggest?