Breakdown of cursor or later missing during writing

[Laptop_fan]

Helo, I have problem with my laptop HP840 G1 i7. During writing cursor periodicaly freez. I lost laters. Only happend at internal keyboard. Not happend at USB keybord. Bios upgraded to last version. What can be done more? Its hardware or software issue?

[WAWood]

@Laptop_fan 

Since this is not happening with the USB keyboard, then most likely, it is a hardware failure with the internal keyboard.

Here's some troubleshooting steps you can try: http://support.hp.com/us-en/document/c03738933

If the laptop keyboard simply does not work, then you will have to plug in an external keyboard and see if you can run the tests using that.

If you are experienced at laptop repairs, you can often replace a keyboard for $25 for a new one and a half-hours work. I have done this on older HP laptops.

But, if you're NOT, there is a serious risk of breaking fragile connectors and cables doing this -- so I do not recommend it.

Instead, I would recommend you hunting down a local laptop repair place to have THEM replace the keyboard. Sometimes, on some models, you have to replace the entire top surface of the laptop, not just the keyboard. So you should get an estimate of what is involved before you have the work done.

[Laptop_fan]

Hello, unfortunately I already done replacing keyboard [3 models] the same behaviour. The same problem ar Win and Linux. Only at USB is ok.  At service they didn't found any root cause. Its can be hardware issue? Problem with CPU or controller? For any help I will be appreciated. 

[Laptop_fan]

After test keyboard by pressing continually from left to right side with the same speed.: 

[Laptop_fan]

[WAWood]

@Laptop_fan 

We have no access to your laptop and can not do any troubleshooting or diagnostics for you.

If the link I provided to test the keyboard showed nothing, then you can try the general diagnostics by pressing the Esc key repeatedly while rebooting and when the HP Startup Menu appears, select the option for diagnostics -- usually F2.

Good Luck

[Arijit_Dutta]

try updating the Synaptics touchpad driver.

[Laptop_fan]

Hello,  not help.  Its possible that hardware issue.  Behaviour looks like:  during typing first or other letter is missing.  Its not connected with letter but rather time of pushing. Even during continuously pushing one letter its stopping during typing. 

Any idea?