1
\$\begingroup\$

enter image description here

What is this tiny square Iphone 4s component with a tiny label of C7 on it?

I bought few damage iphone 4s trying to fix them, one of the phones' PCB is in a pretty good condition, but it's missing that c7 chip. I want to know what it does and is it possible to swap it from another pcb.

enter image description here Here is the photo of the pcb for that missing chip.

\$\endgroup\$

3 Answers 3

5
\$\begingroup\$

That would be U10, RP106Z121D8.
Looks like a 1.28V regulator.

(hint: google the schematics)

\$\endgroup\$
3
  • 1
    \$\begingroup\$ Whoa! Do you mean that the entire schematics for iPhone 4 is available on-line? Very interesting... and it is really there! +1 \$\endgroup\$ Mar 22, 2018 at 8:33
  • \$\begingroup\$ @ali chen, I found it. forum.cxem.net/applications/core/interface/file/attachment.php?id=221384 \$\endgroup\$
    – user83582
    Mar 22, 2018 at 8:51
  • 1
    \$\begingroup\$ @AliChen I did not link it considering possible legal implications. \$\endgroup\$
    – Jeroen3
    Mar 22, 2018 at 8:55
3
\$\begingroup\$

Having looked it up myself I can agree that the first poster is correct about it being a voltage regulator

U10 Schematic U10 Layout

\$\endgroup\$
0
\$\begingroup\$

OK Since posting this I just saw the answer above and if the schematics are indeed available that must be the answer. There are so many small square surface mount ICs. But rather than just delete my comment this is what I wrote without that info (probably wrong):

It's very hard to tell from the photo. What we need to know is how many connections does it have in the land pattern. Some web searching for C7 makes me think it might be a SN74LVC1G17 which has a square package. It has five connections. Four on the corners plus the central thermal pad in one version. It looks more like an integrated circuit to me than a diode or something passive.

The amount of gunk around it makes it hard to tell what the copper pad pattern looks like.

I would check out the texas instruments SN74LVC1G17 Single Schmitt-Trigger Buffer. It makes sense electrically that it would be near a connector because typically a buffer like that is to receive an input from off board which might be noisy.

Annoyingly they seem to have a number of versions of the same chip which are all about 1mm square, with different connection styles, e.g. ball grid, or whatever. I would carefully look at the datasheet and maybe try to expose the copper land pattern of the board and see which it might be.

http://www.ti.com/lit/ds/symlink/sn74lvc1g17.pdf

Update: Yeah it could be a voltage regulator absolutely - with the same package. Probably you'd have to buy one from Mouser/Digikey to see if it looks the same.

\$\endgroup\$
1
  • \$\begingroup\$ Camera is not important to me. I can swap one from other pcb if I want to fix it. I have few bad pcb for parts. \$\endgroup\$
    – user83582
    Mar 22, 2018 at 8:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.