Am 05.11.2010 um 12:39 schrieb Dr. H. Nikolaus Schaller: > > Am 21.10.2010 um 07:36 schrieb Dr. H. Nikolaus Schaller: > >> >> Am 20.10.2010 um 09:56 schrieb Patryk Benderz: >> >>> [cut] >>>> I will keep you updated. >>>> >>>> Nikolaus >>> Thanks for sharing this, do you have some photos of this board? Looking >> >> Here is the photo of a bare board as it came from the PCB factory: >> >> http://download.goldelico.com/gta04/images/DSC00627.jpg >> http://download.goldelico.com/gta04/images/DSC00628.jpg >> >> The next version of the board layout will add two Hirose DF40 >> board-to-board connectors on the display side so that the GTA04 >> can be mounted on a expansion board (e.g. for a different/larger >> display). >> >> A populated board will finally look similar to this one: >> >> http://download.goldelico.com/gta04/images/DSC00477.jpg >> >>> forward to hear more! :) >> >> As soon as we have something to share... > > Ok, > here is some good and bad news... > > Good news: > > last week I got a board where some of the > basic power control chips are populated (except > the TPS65950 BGA). Mainly, the backlight > converter is operating. > > This one works and after connecting a > LCD module, we could operate it as a > lamp :) > > Yesterday I received the second board where we > did populate the TPS65950 (power controller). > > The results of measurements are: > * the 32 kHz RTC clock is operating > * when inserting a battery, most voltages are > available as expected > > Bad news: > > * we have a short circuit on the 1V8 rail > > I have spent most of the night and this morning to > track this down. It appears to be a solder short circuit > under the TPS chip (a 0.4 mm pitch BGA). > > So I am currently sitting at our SMD rework company > and looking over the shoulder of the CTO who has > a lot of experience. Unfortunately I can't make > photos. > > We already have unsoldered the TPS chip (that needs > a really sophisticated machine) and the short has > disappeared. > > The next step is to solder it back again and do the next tests. > > If that works, i.e. we get all voltages from the power controller, > the 26 MHz oscillator should also start working. > > If that is ok, the OMAP and the POP memory will be soldered. > Maybe we manage to get it today. Then, we can see if the CPU > is doing something.
Current status: the 1.8V is now working but the VDD2 (1.2 V) not. The TPS chip aborts the power up sequence early. > Rene will upload some photos of the board and we will > post a link. Here: http://download.goldelico.com/gta04/images/DSC00671.jpg http://download.goldelico.com/gta04/images/DSC00672.jpg > > Nikolaus > > _______________________________________________ > Openmoko community mailing list > community@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/community _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
