Solution to Freezes Caused by Ribbon Cable

Hi Marc,

Didn't have time to read the whole thing yet, but looks like a nice job describing and illustrating the issue and fix! I have no question others will benefit from it. Now, instead of describing the whole thing to other users, I can just link your site. 😉

Haven't heard from Anthony yet, wondering if he's still going to post the tip?

Marc that's an exceptional piece of work. I don't think that I could have out anything better together myself (in fact I'm glad someone got around to it b/c I've been too busy with work for the past few months to do it myself). The illustrations in particular will help a lot of people, very nicely put together.

Off the top of my head there are only a few more things I would add which you may want to consider folding into your blog in some way):

1) Affected machines - any Ti book (not Al books, afaik) other than the 400 and 500 mHz machines. The latter machines do not have the trackpad cable running in the same position. The symptoms of an electrical short can affect these machines but are due to contact in other parts of the machine (see below).

2) Symptoms - in addition to random crashes/hangs/freezes, this problem also results in Tibooks not waking from sleep, a "sticky" or "choppy" response from the trackpad (often the first sign that something is amiss) and the "three beep" memory error when trying to reboot the machine. The latter often leads to concern that something is wrong with the RAM modules in the machine (which always test fine using the Apple Hardware Diagnostics CD) but is likely just due to proximity of the trackpad cable to the RAM banks. The worst part is that, early on, these symptoms are not terribly consistent which makes it difficult to demonstrate to a service tech and prone to suggestion that it is a software problem (e.g. caused by a point update to the OS). Once the damage is more extensive then things become more consistent. That's how I initially found the problem, I noticed I could reliably cause a hang by pressing on the left cmd key or the left side of the space bar.

3) Other causes - there have certainly been people I've corresponded with (including those with 400 and 500 mHz machines) who have experienced identical symptoms with no involvement of the trackpad cable. In some cases, the cause has been isolated to contact between the case and some part of the mobo itself. The most reliable way to check for this is to press systematically along the case (every inch or so, top and bottom) and the keyboard. I know of several cases that were solved with a bit of electrician's tape on the inside of the case at the "pressure point".

4) Why does it happen - Thanks to some input from TJ and some observations of my own, I think we've pretty much figured out that the cable is actually placed in this position during the manufacturing process. This means that potentially, every single Ti book made since the initial generation is at risk of developing this problem (esp. if the owner uses the left cmd key frequently). If you know someone who owns one, get them the "check under the hood". To paraphrase the famous proverb - "Some tape in time will save you from going out of your mind".

5) How to fix it - The question of how to best protect it hasn't really been answered. There is enough "slack" in the cable to gently pry it out so that is can sit immediately to the right of the frame. This is what I prefer since the chance of further damage is entirely eliminated (once you put a bit of tape over the damaged section). Others prefer to leave it in place and insulate it which is easier but means you've still got pressure being placed on the cable from day to day usage. *IF YOU ARE GOING TO TRY TO PRY OUT THE CABLE - TREAT IT VERY GENTLY - USE SOMETHING PLASTIC AND NON-CONDUCTIVE *. I recently heard from a Ti owner who thinks he may have damaged the cable further by using a pair of needle nose pliers to move it out. Once the cable is irreparably damaged, the only solution is to go out and find a complete top case assembly that will fit you machine (this will come with a trackpad cable) and replace the whole thing. Doable (+ expensive) but you've got to gut the machine from the bottom up (HD, DVD, mobo, screen, everything has to come out) - very tricky.

Sorry, ran out of room there.

All I was going to add was to reiterate what a great job you had done on this Marc. It's going to help a lot of Ti book owners.

Thanks for the (hopefully) permanent link, the write up and the credit.

Cheers and happy holidays,
Anthony

Oh and fwiw, I have not had one of these freezes since I moved the trackpad cable in April of 2003.

Back to the top with this one. If you've got a Ti book 550 or faster with problems waking from sleep and/or random freezes and/or three beep "memory" errors with good memory and/or a jumpy trackpad then have a look at Marc's blog for details of a fix. This was originally posted by me but he's done a super job outlining this increasingly common and frustrating problem.

I think I may be having this issue, too... check this thread to see if it sounds similar: Seth Gunderson, "I'm about at the end of my rope...", 10:00pm Feb 2, 2005 CDT

Hey Marc,

Was just looking at your site (yet again; that is good work) for some info on symptoms, and noticed in your last picture (taped after the fix), that the screw wasn't reinstalled . . . just a heads up just in case.

Marc, Anthony or anybody else,

Do you remember if random characters when typing known keys was a symptom in any of the confirmed cases where the ribbon cable fix resolved the issue?

Hi Marc,

I don't remember this particular symptom. Maybe Anthony does. I remember key presses in the area of the ribbon cable causing freezes, but not the random characters being typed.

No, I don't remember it either, but just wanted to make sure before I recommend troubleshooting the cable to someone. Thanks for the reply.

I don't recall anyone with that symptom as part of the trackpad cable issue. Physically the keyboard cable and the trackpad cable are quite distinct and connect in very different locations of the mobo. If that individual is also having random freezes they might have two different problems or it's conceivable that the keyboard cable has been damaged so a close inspection might be wise.

If that individual is also having random freezes

No.

it's conceivable that the keyboard cable has been damaged so a close inspection might be wise.

Sounds good.

Thanks

Last night and this morning, my TiBook froze on me about 8-10 times. It's happened before recently, but not this much. I decided to hop on the discussions and see if I could find a solution. After a full day of usage after applying this solution, I just wanted to confirm that this fix works. Thanks guys!

To help anyone else, here are the symptoms I've noticed prior to the fix:
- Seemingly random freezes
- 3 beeps at startup, along with a quick blinking sleep light
- The keyboard seems to still work during the freezes, as evidenced by the ability for the caps lock light to toggle on and off

Hope this helps someone else.

Hi Marc & Anthony,

another succesful tale of a machine ressurected through the orange trackpad cable repair. Many thanks for all your hard work.

You can read about my particular woes at that thread if you want.

Marc, it may be worthwhile adding the bursts of white noise (after the chimes before the memory Beeps) to the list of known symptoms of the pinched cable as I haven't seen them noted anywhere else...

Lastly I think it woud be good if we could keep this thread bumped up to the top of the board (although tjk is already doing a sterling job of publicising this common fault).

Thanks again,
__
Neil.

Glad to hear it helped Neil. What you may not know is that this thread is actually the second detailing this problem and the fix. The last was pushing 200 posts when it was locked by the admins (too unwieldy). Initially it was posted as a sticky and then it was eventually deleted. I'm not too worried about this one sticking around. It'sa very common problem and an increasingly so as the Ti books age. Plus now that Marc has put together the blog page, it will not be a problem maintaining this as a resource for the community.

Thanks for the fix!

My PB G4 667 was locking randomly, sometimes giving the infamous "three beeps" at reboot. I noticed it would only happend when I held the computer in a certain way, but flat on a desk it was fine. Just another diagnosis tip for anyone else having a similar problem. I was just about to re-install my OS when I stumbled upon your post - saved me hours!