Acer Chromebook 314 Keyboard Fault

NigelS

Can anybody help.

I have a acer chromebook CB314. When the unit is switched on each day, some of the keys don't work. eg g,h,backspace, esc. After about a half hour the device has warmed up and all the keys then work. It's been like this for a couple of days.

Nothing has been spilled on it. Software is up to date. Used in dry conditions

Same fault if used as a guest

It's probably about 2 years old

JackE

Remove charger. Remove 10 screws from bottom cover as shown below. Starting from upper left corner, use a plastic wedge to pry bottom cover from top cover. Move wedge to center of upper part of cover. Then move wedge again to upper right corner. Then to the middle of the right side. Then to the middle of the left side. The base cover should pop off.

Disconnect the battery connector. You may have to remove the battery to access the keyboard connector. It is very near the piece of tape (item B below) that holds battery wires in place on the mainboard, also as showm below. Pull the keyboard connector out. Then push it back in. Repeat a half dozen or so times to help clean the connector contacts.

JackE

After about a half hour the device has warmed up and all the keys then work. > > Used in dry conditions

Sounds like it's caused by hygroscopic debris (like hair, dust, food crumbs) under the keycovers when relative humidity is above ~50%. You might try to gently dig under the keycovers with a soft bristle cosmetic blush brush while blowing compressed air to help loosen and remove the material.

NigelS

Thanks Jack. Same problem this morning. The g,h,backspace, esc keys did not work. Tried cleaning with a fine brush but not convinced it was doing anything. Tried holding keyboard upside down and blowing with hair dryer. The keys still did not work. Left the device switched on for a half hour and the keys are all working again. Its definitely something to do with temperature and or humidity. Thanks for your advice . I'll see how it is tomorrow.

JackE

Keep digging but gently. Key switch covers are hard to get back on if they pop off. I often have to use bent tip tweezers to pull the hair balls out from under the keycovers. Use this keyboard test link to check your progress in removing the debris. If no further progress, you may have to open the machine to re-seat the KB connector a few times to help clean its contacts with the mainboard. As a last resort, you can replace the keyboard. Should be about $30usd but some frustration involved in doing the job.

NigelS

Tanks for te added info Jack. Same aain tis mornin. Some leters missin. Dont understand wy it cures itself wen it warms up.

NigelS

The above comment was written on the chromebook with keyboard fault. This is from the phone. Don't understand Jack, if there is debris under the keys which there may be, why does it start working correctly after about a half hour and then go bad again the next morning

JackE

Heat can cause connector and switch contacts to expand and make better contact if they're a bit oxidized or oily. Sounds like the next step is opening the laptop and re-seating the KB connector a few times to help clean the contacts. What's your full model number? For example, CB314-1H, CB314-4H, CB314-3HT etc???

NigelS

It's CB314-1HT-

JackE

Remove charger. Remove 10 screws from bottom cover as shown below. Starting from upper left corner, use a plastic wedge to pry bottom cover from top cover. Move wedge to center of upper part of cover. Then move wedge again to upper right corner. Then to the middle of the right side. Then to the middle of the left side. The base cover should pop off.

Disconnect the battery connector. You may have to remove the battery to access the keyboard connector. It is very near the piece of tape (item B below) that holds battery wires in place on the mainboard, also as showm below. Pull the keyboard connector out. Then push it back in. Repeat a half dozen or so times to help clean the connector contacts.

NigelS

I'm replying using the chromebook so there's a clue.

Before you replied ,I had the back off last night. Loosened the kb connector ribbon, guessing a bit which connector it was. Pushed the ribbon in and out a bit. Reassembled and kb worked perfectly. This morning same fault.

I read your message and repeated the operation, this time pulling the ribbon fully out and back in a few times. Reassembled and it all works perfectly. So that's what the problem was. I bad connection. Hopefully it will be ok in the morning.

Thanks for all your help Jack. You are a top man and I owe you a beer.

Nigel

JackE

If it's still OK in the morning, prefer an ipa if you don't mind. 🙂 Good luck.