Please try following steps, one step at a time to tackle
make sure that new module is pushed all the way down in to the socket.
Please try again and make sure to push it all the way down and system power
should be off during installation.
turn off the power to your system and remove Kahlon module and use pencil
eraser to clean memory module gold contacts and make sure that memory socket
is also dust free and reseat the module.
turn off the power to your system and try installing Kahlon module in a
different socket if more than one socket is available.
turn off the power to your system and try installing Kahlon module alone in
you are installing memory in Desktop or Tower case then please check to make
sure that all expansion cards are seated properly and no power connector got
loose during memory installation.
you have purchased more than one module and your system can use one module
at a time then try installing one module at a time.
check Kahlon part number and make sure that you have ordered correct module
for you computer.