Re: Hardware mod for starting GTA02v5 without battery?
On Sun, May 10, 2009 at 08:51:39PM +0200, Rask Ingemann Lambertsen wrote: On Sat, May 09, 2009 at 10:36:19PM -0400, Paul Buede wrote: It's a hardware mod. It's capacitor C1767, page four of the schematics[1] at the bottom. There's a (rather poor) picture of a reworked A5 here: http://lists.openmoko.org/pipermail/openmoko-kernel/2008-July/003963.html Much better picture here (from thread mentioned below): http://lists.openmoko.org/pipermail/openmoko-kernel/attachments/20080205/7246629a/attachment.jpg Electrically, the rework is simple enough: Just connect a larger capacitor in parallel to the existing one. But it sits under the main can, so making it fit isn't easy. The picture of the reworked device isn't very good, but it looks like a capacitor has been connected to the VB_SYS side of R1768 and to the GND side of C1722. See also this thread on the kernel list: http://lists.openmoko.org/pipermail/openmoko-kernel/2008-February/000852.html Alternative A5 rework here: http://lists.openmoko.org/pipermail/openmoko-kernel/2008-February/000883.html -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Hardware mod for starting GTA02v5 without battery? (Was: Need battery help in DC area)
On Sat, May 09, 2009 at 10:36:19PM -0400, Paul Buede wrote: Also, does anyone have instruction on how to fix my Freerunner so it can boot off USB or wall charger? Is it a hardware mod or firmwae upgrade or something? It's a hardware mod. It's capacitor C1767, page four of the schematics[1] at the bottom. There's a (rather poor) picture of a reworked A5 here: http://lists.openmoko.org/pipermail/openmoko-kernel/2008-July/003963.html Better picture (of the whole A5 PCB without the rework): http://wiki.openmoko.org/wiki/Image:Gta02a5_pcba_cs.JPG Electrically, the rework is simple enough: Just connect a larger capacitor in parallel to the existing one. But it sits under the main can, so making it fit isn't easy. The picture of the reworked device isn't very good, but it looks like a capacitor has been connected to the VB_SYS side of R1768 and to the GND side of C1722. See URL:http://people.openmoko.org/werner/gta02-chg/ for an explanation of the problems GTA02v5 has starting without battery power. Btw, where is C1767 itself? I can't find it on either the assembly silkscreen[2] or the component placement drawing[3]. At 47 uF on the A6, it ought to be easy to spot. [1] http://people.openmoko.org/joerg/schematics/GTA02/Schematics_Freerunner-GTA02_A5-A7cumulative_public_RC0.pdf [2] http://people.openmoko.org/joerg/schematics/GTA02/GTA02-MB-A6(50-71481-00)_assembly%20silkscreen.pdf [3] http://people.openmoko.org/joerg/schematics/GTA02/Component-placement_Freerunner-GTA02-MB-A6.pdf -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
