Flickering screens can be caused by video drivers. The first thing to try is updating the driver. Another cause can be a low screen-refresh rate. Make sure the rate is set according to the documentation. Keep in mind that if you set it incorrectly, another symptom that may appear is more than one image displaying with the top image appearing transparent.
Flickering can also be cause by a loose connection. You may remember that a cable connects the display to the motherboard.
Problem with keyboards can range from collecting dust (in which case you need to blow it out) to their springs wearing out. In the latter case, you can replace the keyboard (they cost about 10 times more than desktop keyboards) or choose to sue an external one (provided the user isn’t traveling and having to lug another hardware element with them). As you can imagine, spilled liquids are often the cause of sticking keys.
Most laptops today include an internal wireless card. This is convenient, but it can be susceptible to interference (resulting in a low signal strength) between the laptop and the access point. Do what you can to reduce the number of items blocking the signal between the two devices, and you’ll increase the strength of the signal. it is also possible that the cable that connects the antenna to the laptop need to be reseated.
Battery Not Charging
Most NiCad batteries build up memory and that memory can prevent a battery from offering a full charge. The biggest issue with DC power problems is battery’s inability to power the laptop as long as it should. If a feature is available to fully drain the battery, you should use it to eliminate the memory (letting the laptop run on battery on a regular basis greatly helps). If you can’t drain the battery and eliminate the memory effect, you should replace the battery.
No Wireless Connectivity
When there is no wireless connectivity, it is usually one of two things:
Wireless capability is disabled (enabling and disabling this function is usually done with a key combination or a Fn key) as this is very easy you disable inadvertently. This can also be a hardware switch on the side, front, or back of the case.
The wireless antenna is bad or the cable needs to be reseated.