GTA02 power death
Hi everybody, The situation: I've use for a couple of month this battery http://www.ebay.co.uk/itm/Battery-Cell-Fit-RoHS-Garmin-GPS-Mobile-10-GPS-Mobile-10x-GPS10-/300575864789?pt=UK_In_Car_Technologyhash=item45fbb7b7d5 yesterday my device accidently start switching off (after night recharging) and make some strange buzzing on power on without any visible activity (screen was kept black). So I decide that is a known complete battery drain problem and try to animate the device with external power. However, after several attempts I've got it booted. The screen picture was surprisingly inverted (!) but after sleep and awaking procedure it gets normal. After that, I've got idea to measure the battery voltage and found that it is 4.1 v (instead normal 3.7). Eventually I deside to leave it as is and try to find the cause at morning. I switch it off and go to sleep. Today I repeat operation with all similar symptomes (noise on power on without any other reactions) but without any success. Contrariwise, after several iterations of unsuccessful tries, when I power it on with battery and original USB adapter, it suddenly turned on for the second, then screen start gets brigther and finally I feel sweet smell of burning isolation :) I immediately remove all power sources, disassemble the device and found that I've burned some tiny IC near the PCF50633HN. The question: I digg all internets regarding the PCB layout but can't find anything relevant (there is no PCB layout on the wiki?). I suppose that was RT9013 (at least that only component in this schematic block that has similar package) but I'm not sure. Could anybody help me to identify this component? here is HiRes picture of the patient http://www.shalnoff.com/pics/freerunner_pcb.JPG You easily find it by burning fume around it :) except of that would be intereting to get some hints what the real reason cause this situation. And why LiPo battery can start to show 4.1v? I suppose that has some connection to the charging procedure (I use QTmoko without the non-original battery patch). Thank you for any hints in advance! Plan to purchase and resolder it. Dmitry ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
looking for used (or broken) GTA02 (whole or PCB) to purchase
Hi list! Is there anybody have broken screen GTA02 for sale? or maybe intact PCB after upgrade to GTA04? I'll be appreciate for reasonable price or maybe somebody just could give it for free (almost free) after upgrade. thank you in advance! Dmitry ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: GTA02 power death
Dmitry Shalnoff shaln...@gmail.com writes: here is HiRes picture of the patient http://www.shalnoff.com/pics/freerunner_pcb.JPG You easily find it by burning fume around it :) Hi. I think that's the same that happened with another device i did bass rework for. The large shield is too easy to tilt a bit and it can touch the big capacitors shorting something to ground. Nice pals at work helped me to desolder that inductor (with hot air gun) and they found another that was similar enough (see the PMU datasheet), and that revived the device. You can find BOM, component placement etc at http://people.openmoko.org/joerg/schematics/GTA02/ Good luck! -- Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software! mailto:fercer...@gmail.com ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: GTA02 power death
On Sun, Dec 23, 2012 at 10:38:56AM +0400, Paul Fertser wrote: Dmitry Shalnoff shaln...@gmail.com writes: here is HiRes picture of the patient http://www.shalnoff.com/pics/freerunner_pcb.JPG You easily find it by burning fume around it :) ... found another that was similar enough I found some IRC log and it looks like the inductor you need should be rated for = 2MHz and = 500mA current. But i'm not sure about the details, that was so long ago. I just remember that they found something that was physically smaller and of similar specs. Desoldering with hot air requires expertise, i wouldn't probably attempt it myself even now: if you shake the board accidentally, you'll shake off other components too. HTH -- Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software! mailto:fercer...@gmail.com ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
