touchpad not working at all

Discuss peripherals for the XO and power management.

touchpad not working at all

Postby ndemou » Mon Nov 02, 2009 8:23 am

Today I turned on my XO and my touchpad was not responding.

I issued the "test mouse" command during boot and I was getting no dots on the screen. I was about to open the case to look for some unlocked connector when I noticed this strange detail:

if I pressed really really HARD I was getting dots at the corresponding positions of the screen (as if the touchpad was working). In fact even pressing hard *outside* the main touchpad area was producing dots! However from within sugar no matter how hard I'm pressing I get no mouse movement (same with a xubuntu installation I have in a memory card). Only an external mouse works but that's not an option for most of the time.

BTW during the "test mouse" procedure I also noticed that the "PRESURE" indication only shows "UP" and "127" (127 when pressing hard)

Any ideas?
ndemou
 
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Re: touchpad not working at all

Postby change90 » Wed Dec 02, 2009 11:40 pm

Most laptops (if not all) come with a function key. You'll find one near the bottom left. The function key is labelled "Fn" and usually stands out from the rest - either the "Fn" is in a different color or the key as a whole. The function key works in conjunction with other keys on the keyboard especially the ones in the top row marked "F1" to "F12". The combination of function key with these keys lets you perform various tasks quickly such as shutting the screen, putting the computer in sleep mode, switching the wireless connection on and off etc. By keeping the function key pressed and then hitting one of the keys ("F1" to "F12"), activates a task. Thus, on my uncle's Lenovo laptop (and I've noticed this on HP and Toshiba systems too), you can activate and deactivate the touchpad by using the function key with the "F8" key. So if the touchpad on your laptop is not working and is unresponsive, it's not broken, you or someone else has accidently deactivated it with the function key.
By pushing the Fn key down at the bottom left of the keyboard, it caused the Function keys to drop down at the top of the screen, so you can pick out the correct Function key for the touchpad. On my computer it turned out to be the F9 key. All I had to do was hold the Fn key down and the F9 key at the same time to turn the Touchpad on. Hope this helps someone else out there!
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Re: touchpad not working at all

Postby ncarrol » Thu Dec 03, 2009 6:28 pm

Ignore change90.

The problem on an XO is typically caused by a bad connection and / or cable from the touchpad to its electronic board (ALPS board). The ribbon cable comes forward and then bends 180 degrees to insert into its connector on the ALPS board. The cable either loses good contact or micro cracks develop in the cable. Repair requires either reinserting the cable in its connector or replacing the touchpad assembly.

This may show up when handling the XO by its front edge. Sometimes twisting the front edge using its corners will temporarily re-establish the connection. Even holding the XO by one of its front corners may supply enough bending for this.

In any case, the permanent fix requires disassembly with possible part replacement-- search the wiki for disassembly or contact one of the repair centers.
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Re: touchpad not working at all

Postby ndemou » Fri Dec 04, 2009 5:35 am

I've disassembled the XO and reinserted the cables with no luck
Then I've tried cleaning up the connectors with contact spray again with no luck
I'm continuing disassembling just to see if I can find anything else easy to try but any advice is really welcome
ndemou
 
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Re: touchpad not working at all

Postby sandy|XO » Fri Dec 04, 2009 1:31 pm

ndemou wrote:I've disassembled the XO and reinserted the cables with no luck
Then I've tried cleaning up the connectors with contact spray again with no luck
I'm continuing disassembling just to see if I can find anything else easy to try but any advice is really welcome


You may have already poked around the wiki for leads to your touchpad issue, but just to be certain:

http://wiki.laptop.org/go/XO-1_OFW_Self ... iagnostics

The 'test-all' command should lead through to the touchpad test.

The mouse test is started separately as: test/mouse.

What software and firmware is on your XO?

Do you have a developer's key for this XO?
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Re: touchpad not working at all

Postby ncarrol » Fri Dec 04, 2009 8:24 pm

ndemou:

Faced with same symptoms as you (and a similar path of efforts), the replacement of the entire keyboard assembly corrected the problem. This was the simplest since I had a damaged XO as parts.

The problem was intermittent. The reinsertion of the cable in its connector initially solved the problem. It occured again after a couple of months and each "repair" by reinserting the cable became more difficult. Replacing the keyboard assembly is the most practical, if you can get one from one of the repair centers. It was difficult to determine if it was the cable from the touch pad or the connector on the ALPS board.

Getting some response by pressing hard suggested the need for a higher capacitance change to overcome the poor connection or micro crack.

Best.
ncarrol
 
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Re: touchpad not working at all

Postby ndemou » Sat Dec 05, 2009 11:39 am

ncarrol:
Faced with same symptoms as you (and a similar path of efforts), the replacement of the entire keyboard assembly corrected the problem.


by "entire keyboard assembly" do you mean the keyboard the touchpad and the ALPS board along with a little bit of plastics that hold everything together?

Also what was the cost of the replacement (I'm afraid I have to get one too)

BTW I tried to "dig deeper" as I said earlier but there was nothing more to disassemble
ndemou
 
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Re: touchpad not working at all

Postby ndemou » Sat Dec 05, 2009 11:55 am

sandy|XO wrote:[...]You may have already poked around the wiki for leads to your touchpad issue
[...]What software and firmware is on your XO?
[...]Do you have a developer's key for this XO?


I surely poked around a lot and googled a lot and did all the start up tests.

I'm not sure about the firmware and I've left my XO on a bench 15Kms away for the weekend. I did a firmware update some months ago and got a developers key and was happily running xubuntu from an SD card for some months. That's why I see a 99% possibility that this is a hardware issue but if you have any doubts let me know and I will check it (I've seen so many 1% cases in PCs).
________________
PS Thanks for the responses to all of you!
ndemou
 
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Re: touchpad not working at all

Postby ndemou » Sat Dec 05, 2009 11:59 am

ncarrol wrote:The reinsertion of the cable in its connector initially solved the problem. It occured again after a couple of months and each "repair" by reinserting the cable became more difficult.

Does any body know what's the best chemical to clean these connections on the ALPS board -- I've used a Philips contact spray that we aply to metal-to-metal connections but I can't be sure if it's good for those plastic cables with something like a graphite coating that I see in the XO.
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Re: touchpad not working at all

Postby ncarrol » Sat Dec 05, 2009 1:08 pm

ndemou:

Look at this thread:

http://www.olpcnews.com/forum/index.php?topic=3263.0

I replaced the whole keyboard assembly (including ALPS) because I had an XO for parts and I needed the first XO to work 100 % . This involved only disassembly and disconnecting one cable (from connector at hinge area to the ALPS board.

The above thread gives an example where just a new touchpad did not solve the problem, but putting the old one back corrected the problem. This all circumstantial evidence that the cable and / or the connector is the problem.

The black surface on the cable pads appears to be important to the connection. Repeated insertion of the cable seems to wear this and cleaning maked the problem worse for me. I have toyed with recoating the pads / repairing any cracks with a silver paste used for laying down conductive traces on circuit boards. I have never got around to doing this and this could just damage the cable beyond use. Keypad only assembly is about $20 from the repair centers. This all I have to offer. --Nate
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Re: touchpad not working at all

Postby prestonwatson » Tue Dec 08, 2009 5:33 am

Hi ndemou,

There are many suggestion provided to you by the forum members. I hope one of them would have help you to solve your query.

Besides, I don't have a perfect solution to your query. I need to approach some of the experts and find out the best suggestion from them so that you don't have to hang out for the absolute answer.

For this I need at least 3-4 days time. I hope you can bear for a time being.

Cheers.
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Re: touchpad not working at all

Postby ndemou » Tue Dec 08, 2009 9:14 am

prestonwatson wrote:For this I need at least 3-4 days time. I hope you can bear for a time being.
Cheers.

No problem at all
ndemou
 
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Re: touchpad not working at all

Postby timber_blacksmith » Tue Mar 02, 2010 12:34 pm

I've had the opportunity to use/try four XO-1s, loaded with the latest software and firmware and the jumpy mouse problem was easy to reproduce for all. STATIC ELECTRICITY is at work and when the jumpy mouse begins, it's possible to move the mouse simply by hovering my finger over the mouse pad without actually touching it. Upon receiving each OLPC I always cleaned them with a cotton ball dabbed with alcohol, including the mouse pad. My flooring is laminate which is likely creates more static then your average floor especially with slippery moccasins.
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Re: touchpad not working at all

Postby ncarrol » Tue Mar 02, 2010 5:38 pm

The static problem can be made go away by briskly rubbing the hands together and then touching a grounded object.

There is exists in some XO's a separate hardware problem, which I believe is a poor cable /ALPS board connection. That will not go away and requires hardware replacement . That one will not show the mouse movement by moving the finger in the air.
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Re: touchpad not working at all

Postby efc » Tue Jul 19, 2011 10:06 pm

I'm trying to fix an XO-1 running the 10.1.2 release, which I just installed. The XO-1 trackpad was not responding before the firmware update, and it is still not responding now. Oddly enough, both before and now the hardware self-test shows that the trackpad hardware is working (it leaves the trail of dots as I move a finger around the pad).

Why would a pointer in the Sugar (?) OS not respond even when the trackpad hardware seems to be working fine? Any troubleshooting steps to suggest?

Thanks!
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