Iphone 6s plus no front camera

[crea2k]

So iv got a 6s plus here and its driving me insane. It came in originally for a backlight job as on it had royally smoked FL4211 and I had to run a trace as there was no pad left. So insulated the old pad spot, soldered the new ferrite to one end and then the other end that didnt have a pad I ran a trace to the connector from the new ferrite.

Give it back and apparently the front camera doesnt work, the one on the back works fine. So iv tried several cameras and none work, I just get a blank screen.

If I check C3106 with back camera active I get 2.85v if I measure with front active I get nothing.

Attached is my diode map, I have added my measurements in red next to the ones from Mohammeds pdf at the top, and readings from zxw tool at the bottom.

Iv got a Fluke 15B meter.

So we know power isnt a problem I dont think as the 2.85v rail is coming up when the back camera is active. it just shuts down when the front camera is active. I cant see anything really off with the readings really, but please take a look and see what you think.

Iv seen this sort of thing when doing 6 plus touch and it floats stuff on the other side of the board. Looking under the scope though I can see perfectly healthy solder joints, nothing like the janky crap you see when the component is just perched on the pad.

[Sly]

Worth have a quick look at pin 15 maybe...

Here's why:
The only reason is that every one of your measurements seems to compares to Mohamed's measurements when taking the relative differences between the two meters being used.

Pins 15,16,17 should essentially be the same. Your measurements for pin 16,17 are the same, but not 15. It's not a huge difference but zxw has those with a 0mV differences. Mohamed has a slight difference of up to 3mV between the 3 pins. Yours has a difference of 19mV. on pin 15.

What could cause it?
That could indicate an increased resistance on that line. It goes straight to CPU via one filter. You could check quickly that your connector is free from flux, the pin is properly soldered to the board, and that the filter is properly connected, or not blown. The one capacitor on that line is connected before the filter, so you might be getting voltage drop from the cap to pin 15 and skipping the cpu if the filter is blown, or disconnected.

[crea2k]

Thanks !, I did notice earlier that they didn't match, but then didn't think any more of it as they are cpu lines, so if dead there isn't a lot can be done. I never thought about a partially blown filter. Good call il check it out !

[crea2k]

Thinking about what's been done and what iv seen before I think it's possibly a bad contact to pad from the filter as I think I tested the filter itself .

[Jessa_the_Professa]

The 6s often gets an OL joint to fcam, there is a separation in the enable for fcam and rcam (iirc) in the 6s compared to the 6. When i'm troubleshooting weird stuff like that and nothing seems obvious to me, i jump all the filters to rule them out while troubleshooting. I would think a bona fide CPU problem would be OL to CPU on diode mode. I think a lot of these data signals are simple ones, so if you really wanted to go down the rabbit hole you could compare to known good and see if you could find an enable or reset voltage that is missing. Other than that---let's think beyond fcam. Is there anything else that could disable fcam--some kind of strobe thermistor or something farther afield that could be specifically disabling it.

[crea2k]

Thanks for the replies. I sorted this in the end by removing that filter and re soldering it. Odd as it didn't have the usual (I'm going to fall off the pad at any second) look to it, so god only knows. One end did look a bit janky so probably that. Unusual for me to get trolled by filters after work as iv seen it a hundred times before with touch ic and cameras not working but we got there in the end .

[Sly]

Lol, Louis tagged him self as god

[Sly]

Nice, so you got it back working?

[crea2k]

Yes all working now