Resurrecting a cellphone with blown USB circuitry

[Script] is pretty lucky. One of the engineers who designed his cellphone included over-voltage protection in the circuit. Of course you probably wouldn’t know about this if there wasn’t a service schematic available. But a bit of searching around let him resurrect the fried USB segment of his Nokia N900.

Now [Script] has been experimenting with portable solar power like the system featured at 25C3 a few years back. Unfortunately he made an error which routed 12V into the USB connector’s 5V rail. After this unfortunate mistake the phone would not longer connect via USB, or charge the battery. Luickly the N900 is a favorite with the hacker community (you can see all kinds of N900 related projects here at Hackaday) and [Script] found his way to their N900 Schematic page. Digging into page four he found part F5300 which is labeled 2.0A. He removed the PCB and shielding, and tested the part with a multimeter to confirm it was blown. A quick wire bridge got the phone charging again, but [Script] plans to position a new fuse as soon as he can source the part.

Who says these devices aren’t user serviceable? If we could just get our hands on more service schematics perhaps our gear would last longer.

Hard resetting your Ford Touch system the easy way

ford-sync-reset

[Jeff Clymer] owns a Ford Focus, and while he’s generally happy with the car, the “My Ford Touch/Sync” system can be buggy at times. He spends a lot of time in the car each day, so when the entertainment center locks up as it is frequently known to do, he has to turn off the car and pull a fuse to reset the system. Since pulling a fuse while on the road is pretty impractical, he decided to install a reset button, making system reboots a breeze.

He started by disassembling various fuses until he found one with an easy to remove fusible link. Once it was in pieces, he soldered a pair of wires to the fuse terminals and connected everything to a normally closed momentary pushbutton switch. After adding an inline fuse holder and reinserting the original fuse, he installed the button into the back of his glove box

Now instead of physically removing the fuse each time his stereo locks up, he can simply push a button and be on his way. Here’s hoping a software fix is coming for [Jeff’s] car sooner rather than later!