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I have an Asus Zenfone AR which has had the screen replaced 3 times. Last time I replaced it myself, Asus the first 2 times.

Screen replacement went fine but once together I discovered up volume button didn't work. Upon further investigation, I have found that playing with the 7-conductor flexible PCB cable, I can get the up button to work but not the down button, and sometimes, if I'm luck, maybe both but then not the power button.

I'm quite confident that the problem resides with the flat cable connection to the motherboard. During assembly, the little white connector, which folds up and down like a lever to press the flexible PCB cable against contractors, popped off, and I've had trouble getting it to stay on. I wonder if maybe the locking connector, what I'm calling this:

enter image description here

Is maybe fatigued? Also, due to its very small size (~5 mm wide) it's hard to even understand what orientation it goes in.

I'm hoping somebody can help me ID/source the white connector. It's my hope that a new connector that didn't pop off will put enough pressure so the cable stays in good contact. Here are some more photos:

enter image description here enter image description here enter image description here

And here I took the liberty of drawing up the connectors because they're so hard to photograph:

enter image description here

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  • \$\begingroup\$ Also, any other suggestions on how to circumvent this issue are welcome. I considered using a non-conductive adhesive to glue this ribbon down but didn't want to go that route unless I was out of options. \$\endgroup\$ – DrTarr Jan 22 '19 at 17:18
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  • 2 possible issues; contact force and contaminated contacts from skin oil or humidity. ( unlikely broken SMD solder joints but possible, if you press on board connector only without stress on FPC and that works.)

The receptacle and plated FPC contacts must both be gold plated but this comes in a wide range of quality and corrosion may still be possible in high temp/humidity with ocean salt spray in the air.

These are gold plated Flex printed circuit contacts or FPC. They come in a wide range of FPC thickness from 0.2mm and up. If the replacement has a thinner FPC then the contact tension is unreliable. Putting a polyamide tape spacer ( which also come in different thicknesses) might work but tolerances between won't fit and too lose are tiny.)

Suggestions

Feel insertion force for tiny snap fit from edge of flexible thin polyamide FPC on the sloped receptacle spring contact. If none then a spacer might be needed thinner than the board using special tape called Kapton that looks like the FPC cable.

Clean FPC gold contacts with "pink pearl" pencil eraser.

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The latches can become fatigued, but usually can be popped back into place. In the past I have had to use a bench scope so I could see what I was doing. The latch keeps the pads on the flex cable in contact with the pins of the connector. I would recommend finding a microscope and you should be able to pop it back into place with some tweezers. The tabs look like they are still there, sometimes one of the tabs can get detached and then you would ether need to become very creative with glue or find a new connector

It is unlikely that you will find a replacement for this connector, if you really need a new tab, the best place to find one would be on another device (if you could source a cheap broken version of the board). If you did find the same connector, your best bet would be to solder it on, not replace the tab.

You could always use kapton tape to secure the tab down also.

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