Sixth iteration of Apple iPhone, announced on September 12, 2012. Repair of this device is similar to the previous models, requiring screwdrivers and prying tools. Available as GSM or CDMA / 16, 32, or 64 GB / Black or White.

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Black screen with light at edges from missing cap

Hi, After replacing a cracked iPhone 5 screen, the new screen worked OK but I opened it again to remove the logic board as the rear camera was not working. After replacing the camera, the screen did not work, it is black when turned on but with the screen lifted away from the case I can see white light at the edges. Otherwise the phone works (vibrates etc).

I have searched this forum and many others and see that a common solution is to test/replace some filters, coil, ic etc. But I have a slightly different problem I think. Near the power connector J6, I accidently flicked off one of the caps. This is C9 from pin 7 which looks to be the main voltage to the components.

Just wondering if this could be the cause of the screen problem. Although I know that I need to get this fixed, given that this part of the circuit looks to supply power to many components, I wonder if for some reason the screen is impacted while the rest of the phone seems OK.

Thankyou for your help

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Chosen Solution

C9 is not involved in the backlight or image generation circuit---don't worry about it.

Look closely for damage near the LCD connector and try a new screen.

Keep us updated

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Hi, I have had a good look around the connector and components in the area and it looks OK and I have tried a second screen but with the same result - black screen with white light in the back. Are there any tests that I can do with the multi-meter to try to narrow the problem down but without having to remove components. What is the next step to sort this out. I am in Australia and I am having trouble locating anyone local that does logic board repairs and it is beyond my own skills.

Thankyou

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This is definitely a board-level repair---there are sites out there that have an extensive knowledge base of iPhone board-level problems, some free, some pay-for-solution. A board-level fix is going to require replacing components on the board.

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OK, I will start looking for someone that can diagnose and repair. One place I rang in Brisbane knows nothing about iPhones and do not keep specific components but are able to micro solder (although removing the shield may be a problem for them I think). I have found one place that sell the digitizer components but cannot find anyone that sells the broken C9 component. Do you know where this can be sourced. Also, do you know what its function is. Given it is off vcc and goes to earth along with a couple of others I thought that it may be to prevent voltage spikes.

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you'd source these kinds of components off a dead iphone 5 board. C9 probably doesn't even need to be replaced, it is just a tiny non-critical 56 pF cap. The loss of it doesn't break continuity through the line.

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just got back to this. I tried cleaning all around the LCD connector with alcohol as I could not hurt but alas no luck. I am just wondering if this is a 'no back light' problem or a 'broken LCD problem'. The screen does light up dimly, but there are no images displayed at all. In other posts, people have described being able to see a very dark image (I guess as the back light does not work but the LCD does) with the no backlight problem. Are these 2 completely different problems with different components to be replace or does it all come back to the IC, coil, filters etc. Thanks

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Paul, you did not tell us when you "flicked off" C9. If your display worked before this happened but quit working after, then I would suggest you replace the cap. If it did not, then you may have a display issues. It does sound like you are not getting proper backlighting.

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Hi, I am sure that C9 was flicked off when I was removing the logic board which was after the screen was initially replaced and working. The screw driver was too big for the job so would not seat into the screw and came off. So it does seem the likely cause but given this component seems to be not specific to the screen display then maybe it is not.

The reason I want to be sure is that if I am taking the phone to an electronics shop, I would just get them to replace C9 only but if it is likely that the other suspect components need replacing then I would also source these and have them replace at the same time. The second option will cost a lot more however.

Thanks

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