CF-53 Keyboard fault

Hi, first time poster and new to the forum. I recently purchased a CF-53 MK2. It came without a hard drive. Installed one and Windows 7 64 bit. On starting the laptop I noticed that some keys would display incorrect characters. For example, if I pressed the letter s, it would display "asdf". Keyboard was replaced with a good one. No difference. I partially dismantled the laptop and cleaned the ribbon connection between the keyboard pcb and motherboard, ribbon connection between keyboard and keyboard pcb. I also cleaned the keyboard with alcohol and dried.

The laptop initially displayed all typed characters correctly. Now, internittently, if I press the s key I may key it printing asd. If I press the w key it displays "we". All connections were tested for dry joints. The keyboard is performing much better but not perfect.

Any ideas?

Thanks

 

Is numlock on?
Is the correct keyboard selected in the OS?

 

Hi. I have tried with a DOS startup disk and a good identical keyboard from another CF-35.

Same issue.

 

I have had that problem before.
I am trying to recall what the issue was. I am thinking the cable was not fully inserted on mine.

I know you already checked, but check the connector that the keyboard goes into.

Is the cable fully inserted?
Is there any debris in the connector?

Post some photos of the connector and cable.
One with cable still inserted and one without.
Also one of the cable.

 

Numlock is not on and correct Keyboard is selected in OS. This must be a hardware problem as the keyboard behaviour is the same if I start laptop with DOS disk.

I did dismantle the laptop previously to get to the keyboard connections on the motherboard which I cleaned. There was an improvement. I found a keyboard connection on which had a voltage of 2.6V instead of 3.3V. This was with the keyboard disconnected. When I cleaned all keyboard connections with alcohol and dried I then had 3.3V on it. There was an improvement with keys as multiple ones were not working correctly initially. An example is pressing key "a" would display asdf.

Current state is:

Pressing "w" produces we
Pressing "s" produces sd
Pressing "x" produces xc

Ctrl key bring up the start menu and a help popup. I suspect a possible dry joint which will mean dismantling the laptop again. Initially after cleaning and reassembly all keys were perfect except for the Ctrl key and windows start key.

I am looking for some tips in case someone has seen this before.

Thanks

Thanks Shawn, I should be opening it up tomorrow and do as you have advised. Will also look at all keyboard connection solder joints under a microscope. May even go over them with some fresh solder with a very fine tip soldering iron.

 

CF 53's have various motherboard and video "issues"

 

Reseated ribbon connections but will check.

 

Not to be insulting, but are you aware that you need to flip or lift the brown clip to properly insert/ remove those cables?
I have seen many people who are not aware of that.

Check around motherboard connectors at top rear of MB. Look for scorching and or burn marks.

 

I will not take offence although I have been repairing computers since 1991. Never been a full time job though. Some component level repairs on motherboards. I will inspect thoroughly. Thanks

 

Some photos of my DOA CF 53.

 

Never had an issue with CF 51 or CF 52.
My past 3 CF 52's They all had over 20,000 hours when I swapped them out.
Swapped because I could. They were still working fine.

 

Thank you very much for the photos. I will have a much better idea of what to look out for based on your past findings. Just what I was looking for. Greatly appreciated.

 

HI Shawn. Issue resolved. I dismantled the laptop. Using a microscope I found 2 microscopic wires that were bridging 2 connections on the keyboard connector. This was on the motherboard. There were no dry joints or signs of burning. Keyboard input is now perfect.

I am very pleased to say the least .

Thanks once again

One small problem though. Pressing Crtl opens the start menu. Not good if I press Ctrl C to copy. Any ideas? Thanks

Sorted. Uninstalled keyboard driver and restarted. I must have installed Windows with an external keyboard connected.

 

Thanks for the info!

 

Your welcome, it is all about sharing info. This is a great forum.