Resetting the BIOS or the motherboard may fix CHECKSUM ERROR.
To do this, try resetting the jumper on the motherboard.
This will change the BIOS setup to factory setting.
Please see the following description for more information.
Jumpers are small pins on the board with plastic or metal devices that go over the pins. This device is called a bridge or a jumper cap. When the bridge is connected to any two pins via a shorting link, it completes the circuit and a certain configuration has been achieved.
A metal bridge that closes an electrical circuit. Typically, a jumper consists of a plastic plug that fits over a pair of protruding pins. Jumpers are sometimes used to configure expansion boards. By placing a jumper plug over a different set of pins, you can change a board’s parameters.