820-3437 No camera

SoloHarty

New member
Hi,

I've got an 820-3437-B that won't recognize the iSight camera. Board was liquid damaged and had no backlight, no battery charge, wouldn't run on battery etc.

Fixed everything except this last issue. Checking U3900, PP0V675, PP1v8_CAM, PP1v35_CAM and PP1V2_CAM are all present during boot but as soon as it gets to the login screen, all voltages disappear.

Am I right in thinking the U3900 is faulty? I've replaced the iSight camera cable and all sensors work.

Thanks!
 

SoloHarty

New member
Wouldn't it be easier to just replace it or are there different factors at play here? Kind of frustrating that this is the last issue and everything else is working great now.:(
 

SMMRepair

Member
Pretty common failure on 3437...board works fine but no camera. We confirmed it was U3900 on one of the dozen+ we've had with the issue. Not worth the time/effort/headache. That chip is a bitch to replace. Leave it as-is and sell it with camera not functioning. You'll be glad you did!
 

SoloHarty

New member
Thanks for the info. Can I ask what makes it a bitch to replace? I can see the chip is thicker than other ones but is it a problem with pulling pads? multilayered BGA chip like the iPhone compass IC?

Thanks again guys!
 

SMMRepair

Member
The balls are super small. SMC is a larger chip, with larger balls, and has ~157 balls. U3900 is smaller chip and has ~208 balls...very, very small and very easy for them to "run". It's also "CRITICAL", so you fuck it up and you now have a non-working board. Just not worth the risk/hassle/pain for a no-cam issue, really. People HAVE done it--I've done 1 of them, and I had to re-ball the chip twice before I even got it on the board. It just wasn't worth it. Took like 3-4 hours, and it was not fun. The time you spend repairing it will cost you more than the loss you'll incur with a no-cam, but working, board.
 

SoloHarty

New member
Ah right, I got you now. Yeah that sounds like a pain in the ass. I kinda wrote off the cam after I got to the conclusion of U3900 anyway but this just sort of cements the decision!

Only joined today and already this is a great forum!
 

dukefawks

Administrator
Pull it off a donor board and see why this is a bitch. 0.25mm balls, no stencil available. It can be done, but I usually don't bother.
 

phuketmymac

New member
Sorry guys but...

What if we buy them online, like on Aliexpress?...

Please don't me they are programmed?!... I have just removed one
 
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