Lenovo Yoga 2 Pro SMD connector intermittent connectivity issue - Page 1
Forum section: electronics / repair

author: dominicM
author_rank: Regular Contributor
timestamp: April 21, 2020, 06:37:46 pm
content: I have a Lenovo Yoga 2 Pro and it seems it has a manufacturing/design defect where the ribbon connector doesn't make good contact. This causes wifi to stop being detected though Bluetooth still works.I tried replacing wifi card so that is not the issue, I also replaced the entire wifi board and Ribbon cable from another faulty laptop. Unless both of these had same damaged part then neither of those are at fault. Often if I clean the connector with isopropyl it works but if I shake the laptop or tap the connector it stops working on power on. Both the connector and cable look clean. I even tried gently bending the pins inward to make better contact but it made no difference. I ruled out MB connector so I am quite certain it is "RIO" connector.I think what might be at least partially at issue is that the cable is a just a little too long causing the battery to push the connector away from it. There is nowhere to tuck the excess in though, its just too little excess cable, were talking 1-2mm. Either way contact should be better than that when connector is fully and securely snapped in.Does anyone have any possible fixes for this? Any way to make the contacts bit less sensitive to movement?

author: aqibi2000
author_rank: Regular Contributor
timestamp: April 21, 2020, 08:08:53 pm
content: How did you rule out the motherboard connector and not the RIO? How did you distinguish this?Put 2-3 layers foam to hold the connector pressed against the board when the cover is attached? But please answer the above first.

author: dominicM
author_rank: Regular Contributor
timestamp: April 22, 2020, 12:03:08 am
content: I believe it is RIO connector as cleaning it with alcohol and reconnecting would fix the issue and tapping/pressing on it would often bring back the issue. With battery in place there should be no movement that would extend to the other connector from any movement related to RIO connector. I did try pressing on the connector with my finger a couple of times but that did not work so I doubt that its an issue with pressure from the top at least.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: April 22, 2020, 12:12:16 am
content: It could be putting pressure on the connector bends the pcb and makes a different component make connection.I had a similar problem with a pcb, twisting the pcb gently made it stop working.I found an unsoldered joint on a resistor.

author: wraper
author_rank: Unknown
timestamp: April 22, 2020, 12:15:26 am
content: IMHO it's red herring. Simply your connector cleaning coincides with taking it apart, causing mechanical stress or doing something else. Also you have BT/WIFI of the same card, so it sounds strange. Does wifi card disappear from device manager or what?

author: wraper
author_rank: Unknown
timestamp: April 22, 2020, 12:31:21 am
content: QuoteAnd what, did you get it ever working at least for short time? Did it appear in device manager and let driver to install? Just in case not every wifi card will be working in random laptop, even if it fits perfectly. By ribbon cable, do you mean you have another exactly the same faulty laptop? Did you replace the board where wifi card is plugged in?

author: dominicM
author_rank: Regular Contributor
timestamp: April 22, 2020, 09:26:03 am
content: Yes I have identical laptop with faulty motherboard and I replaced both the wifi board, wifi adapter and ribbon cable but it did not change anything. I can get it working after cleaning quite reliably. I am also gentle connecting it so unless pcb issue is close by its unlikely that I move anything else further away. Both boards also look perfect. When I say it works I mean wifi connects automatically and appears in device manger. When it stops working only Bluetooth appears even though it is on the same wifi adapter, this to me seems like 1 or few bad contacts. If I remove card completely bluetooth is gone too so bluetooth is definitely on same card.

author: wraper
author_rank: Unknown
timestamp: April 22, 2020, 09:54:58 am
content: Try covering wifi card pins like explained here:https://thecomputerperson.wordpress.com/2016/11/04/how-to-mask-off-the-wifi-power-off-pins-on-m-2-ngff-wireless-cards-the-old-mini-pci-pin-20-trick/

author: dominicM
author_rank: Regular Contributor
timestamp: April 22, 2020, 05:14:18 pm
content: Masking did not work. I am quite convinced that its a mechanical issue caused by cable excess/bulge getting pushed by the battery and causing one side of connector to lift. It's quite obvious from the side at times. No idea how to fix it, the cable is too stiff to tuck under pcb and too short to fold over.