"wen u push the power button nothing happens"
Please confirm you mean there are NO beeps/sounds, arm LEDs, any small LEDs on the main ESC board, camera LED, camera stabilizing, or any response at all from the system when it does not start.
There is some history of start/stop issues with H Plus and adverse interactions with QGroundControl, but I believe all of those involved at least some response during the failed starts. I also don't believe they were intermittent. When it failed, it stayed failed until the issue was resolved.
If there is no response at all:
Have you tried with a different battery?
Is there any evidence of bad battery contacts?
Do you have another On/Off button you can install?