Hi chirath,
If you haven't already, I recommend checking to see if the PSR-E453 has batteries installed. Open the battery compartment cover located on the instrument’s bottom panel and remove any installed batteries.
Remove any cables and USB devices that may be connected. Make sure the power adapter is properly connected. It is best to have a technician check whether the power adapter is OK. In any case (even under load) it must have a stable voltage of 12 volts DC. If possible, use another, equivalent power adapter (12V DC, min. 1.5A / 16.0W, tip = positive pole).
You could try whether the internal Test program can be started:
While holding down the keys [C#2], [F2] and [G#2] (= C# major chord in the second octave) simultaneously, press the [STANDBY / ON] switch. When the test program is started, “TEST” will be shown on the LCD. If this works, please report back here. If it doesn't work, only a Yamaha service technician can probably help you.
Best regards,
Chris