comparison pirelli/undersim @ 9:7a84f9e42a84

Pirelli PCB: failed attempt at tracing out the 4 under-SIM test points
author Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
date Fri, 19 Apr 2013 21:31:47 +0000
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1 There are 4 test points accessible from the battery compartment under the
2 SIM card slot. I shall number them as follows:
3
4 B
5 A (battery connector)
6 T
7
8 +-----+
9 | |
10 | SIM |
11 | |
12 +-----+
13 1 2 3 4
14
15 i.e., the test point closest to the headset jack shall be numbered 4.
16
17 TP 1 and TP 2 have tiny vias inside the TP pads themselves; these vias
18 appear to go no deeper than L2.
19
20 TP 1: on L2 it crosses over the tiny via coming from L1 to a larger via
21 that penetrates almost the entire layer stack. On L7 the latter via
22 connects to a trace. The latter trace runs at normal signal thickness
23 until it hits yet another via. On the other side of that via, still on
24 the same L7, there is a dead-end arm of what appears to be the same net,
25 and the latter arm is thick - almost as if it acts as an antenna of
26 some kind. From there the connections are unclear, but it appears to
27 connect a bunch of fat traces and possibly even copper fill on other
28 layers, so it's unlikely to be an interesting signal.
29
30 TP 2: on L2 it goes to a trace, that trace goes to another via at image
31 coords (4378,1746).
32
33 TP 3 connects to a via; that via appears to make a solid connection to
34 the copper flood-fill on L6.
35
36 TP 4 is connected to the L1 GND copper fill with thermals.