FreeCalypso > hg > freecalypso-reveng
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> |
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date | Fri, 19 Apr 2013 21:31:47 +0000 |
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8:a06573cacb6e | 9:7a84f9e42a84 |
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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. |