Hi @manjunathamanju
Use a strong light and a magnifying glass and visually inspect the phone's charge port enclosure, to make sure that there's no lint etc, in the port enclosure, that may be preventing a good electrical connection between the charge cable plug and the pins in the port. Also make sure that all the pins (5) are there and that they're all straight and parallel with each other and not that they're bent or even missing.
If there is debris in the port enclosure, ''do not'' use a metal pin or probe to try and clear it. Try using a vacuum cleaner instead and check if that clears it. If still no good, use a wooden toothpick to ''gently'' clear any debris from the port.
If the port seems clear, try the following to determine if the USB port connector is loose from the systemboard. Insert the charger cable into the phone's USB port ''only, do not'' connect the other end of the charge cable to anything!
Then take a firm hold of the phone in one hand and with the other hand grab hold of the charge cable plug which is inserted in the phone and ''gently, stress gently,'' try moving the plug up and down and side to side and check if you can feel any movement at all in the port, indicating that it may be loose.
If there's no movement or even if there is then the phone will have to be opened so that a) if there is movement, the USB connector can be resoldered back onto the systemboard or b) if there is no movement, that the phone 's power input circuit can be checked using the schematics in the [https://www.electronica-pt.com/esquema/telefones-moveis-pda/nokia-microsoft-smartphones/microsoft-lumia-430-rm-1099-76052/|service manual]. Start on p.29 (of 39) in the manual
Here's a [https://www.youtube.com/watch?v=kpxpR-oO9-Y|video] that shows how to disassemble the phone that may also help.