Since I had a damaged U801 I/O chip (SN74CBTD3384CPW) I needed to figure out the connections between the sim card holder to this I/O chip to check if every connection were fine. So I had made a small schematic from it and I like (of course) to share it, just in case you need it. Click picture to see it fully.. FYI, These chip can also be found in the Dm800HD, DM800SE and DM500HD.