Broken keyboard/trackpad cable connector

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Broken keyboard/trackpad cable connector

I was doing some work on my 17" powerbook G4, and in removing the top case, accidentally detached the connector holding down the keyboard/trackpad ribbon cable. I soon realized this would, among other things, prevent me from turning the computer on, so, with the advice of the Apple Store, bits of Kapton tape are now holding it together. I can use the keyboard this way, albeit with a few quirks, but the trackpad is totally out, and only once responded when manually pressing the connector to the logic board.
While I can use a mouse, I'd obviously rather have the trackpad working as well as normal keyboard functionality. Can the connector be soldered back onto the logic board, or reattached in another fashion well enough to ensure full operation?
I really don't want to have to buy a new logic board...

17" 1GHz, Mac OS X (10.4.8)

Posted on Jan 9, 2007 6:47 AM

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Answer 1

Jan 9, 2007 12:43 PM in response to Hassouni

Hi Hassouni,

It depends on how the connector became detached. If it left the solder pads/traces on the logic board, due to a weak initial solder, yes, if it pulled off the traces, no. Usually the solder pads will be grey/silver and if the traces have been pulled off, the area will be light brown from the fibreglass substrate.

I suggest you find somewhere that does Surface Mount Technology (SMT) circuit-board repair and see if they can help you.

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Answer 2

Hassouni Author

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Jan 9, 2007 9:18 PM in response to Alex Dawson

the solder pads are still there, though the little metal clips that the plastic part fits over have been pulled off.

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Answer 3

Jan 9, 2007 9:29 PM in response to Hassouni

Hmm I'm not quite sure what you mean, but if you can find a place to repair it, they should be able to help.

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Answer 4

Hassouni Author

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Jan 9, 2007 10:00 PM in response to Alex Dawson

Basically, the part that's soldered down are two little pieces, perpendicular to the logic board, that the connector clips onto have detached. the actual soldered bases that they connect to, however, are still on the board.

it looks sort of like this __| | _, with the vertical part being the broken piece.

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Answer 5

Hassouni Author

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Jan 10, 2007 1:22 PM in response to Hassouni

OK here's a stock picture of the connector (not mine)

https://jshare.johnshopkins.edu/cfranck1/connector.jpg

The white locking bar came out a while ago but this never caused any problems. I don't know if it's supposed to be detachable or not. What came off is the beige part, which fits over two metal tabs sticking up from solder patches approx. where the green highlights are. After trying to reattach everything, the tabs broke and are now inside the connector.

Is that whole thing, under normal circumstances, physically secured only by those two tabs? As it's holding together now, those two areas are definitely contacting the connector, so I'm not sure why the trackpad wouldn't work.

Anyway, now that I've given about as much detail as I can, would soldering be a fairly risk free way to repair this?

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Answer 6

Hardy Geer

Level 4

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Jan 10, 2007 1:22 PM in response to Hassouni

The part between the tabs holds the connections on the top of the flat cable up against connections in the connector on the mother board.

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Answer 7

Hassouni Author

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Jan 10, 2007 1:34 PM in response to Hardy Geer

The part between the tabs holds the connections on
the top of the flat cable up against connections in
the connector on the mother board.

Yeah that's what it seemed to me as well. When it's not broken though, there's no pressure holding it down other than the connection with those tabs then, right? How is it now when there IS pressure holding it down, it's screwy?

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Answer 8

Jan 10, 2007 2:49 PM in response to Hassouni

Ahh ok, I think I understand a bit better now.

The white bar is not supposed to be removable.. no. I suspect your problems relate also to the lack of the white bar. The white bar pushes the FPC cable onto the contacts and makes a more reliable electrical connection. I'm surprised it worked before, but in pushing it down, you may have pushed down the bushes that make contact with the FPC, so they don't spring up as easily anymore, which has made the connection less robust.

As far as repair goes.. I'm sure it could be done, by replacing the whole connector (ie, desoldering what's left of the existing one and replacing it with a new one).

Or you could just use a mouse 😉

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Answer 9

Hassouni Author

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Jan 10, 2007 7:17 PM in response to Alex Dawson

The white piece is still there, it's just not permanently attached. I can still get it to clip in. perhaps if i taped that part down more securely?

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