Errors without messages, Problem | Lenovo W700ds instruction

If one of the following error code messages is displayed on the screen, have the computer serviced:

02F4: EISA CMOS not writable

02F5: DMA test failed

02F6: Software NMI failed

02F7: Fail-safe timer NMI failed

Fan error

Thermal sensing error

Errors without messages

When I turn on the machine, nothing appears on the screen and the machine does not beep while starting up.

Note: If you are not sure whether you heard any beeps:

1.Turn off the computer by pressing and holding the power switch for 4 seconds or more.

2.Turn it on and listen again.

Solution:

1.Make sure that:

vThe battery is installed correctly.

vThe AC adapter is connected to the computer and the power cord is plugged into a working electrical outlet.

vThe computer is turned on. (Turn the power switch on again for confirmation.)

2.If a power-on password is set:

a.Press any key to display the prompt for the power-on password. If the brightness level of the screen is low, increase it by pressing the Fn+Home.

b.Type the correct password and press Enter.

3.If these items are set properly, and the screen remains blank, have the computer serviced.