LG KP152 hard reset

You can use LG Mobile Support tool to repair some LG cell phone model, after download select menu Customer Support > Recovery Phone

LG KP152Q repair
Check Battery Voltage > 3.35V if NO you have to charge your battery or replace it.
Press power-on key and check the level change of POWERON

if NO Check the contact of power key or dome-switch

Check the voltage of The LDO outputs at U101
if NO Replace U101 (V_EXTL=1.8V, V_EXTH=2.8V, V_MMC=2.8V
V_SIM= 1.8 or 3V, V_USB=3.3V, V_RTC=1.8V
V_IO=1.8V, V_ABB =2.8V, V_MEM=1.8V ,
V_PLL= 1.3V)
If it is OK replace the main board.

General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.