Nextar LT43 GPS
If you plug your GPS in and set it on the passenger seat of your car or ask your passenger to hold on to it. Your GPS may end up on the floor.
After several landings on the floor of my car, the mini usb jack was damaged and my GPS could not be charged or powered externally.
If the usb mini jack is damaged on your GPS the information on this page may help you. But before you start tearing apart your GPS you should verify that the usb jack is the problem.
If your GPS won't power up you should determine if your power adaptor is working properly. If the adaptor is not working it may have a blown fuse.
On the adapter in the photo you have to unscrew the end cap to expose the fuse. The end cap on my power adaptor was on so tight that it wasn't obvious that it was removable.
If you open up your GPS and look at the mini usb port connections it looks very intimidating, providing your vision is good enough to see it.
To remove the mini usb jack you need to sufficiently heat the metal shell of the jack. You also need to unsolder the 5 electrical connections. Your goal is to remove the jack without lifting any of the circuit board pads.
Anyway with the jack removed or basically ripped off the circuit board in this case and not recommended I can continue to the next task.
Now that the jack has been removed you can see 5 small pads and what is left of 4 large pads that are the ground pads the mini usb shell was soldered to.
Adding 5 Volt Power Lines
Of the five small pads the outer most pads on the left and right sides are for the 5 volt power connection
In the picture to the right and the image above it you can see that the power lands are much larger than just the original pad area that had solder on it. By scraping off the green coating you now have a very reasonable area to solder wires to and connect external power to the GPS unit.
I would recommend gently removing the coating with a small X-Acto knife. After you remove the coating you can tin the pads with solder.
Mini usb jack pinout reference drawing to help determine the location of the +5 volt power and ground pads.
1 - +5 Volt Red wire
2 - Data - White wire
3 - Data + Green wire
4 - A plug signal to ground, B plug n.c.
5 - Gnd Black wire Signal Ground
I have the new power lines soldered to the GPS circuit board. When I am done with the wire connections I will secure the wires with a two part epoxy mix.
Warning: If you apply more than 5.25 volts or apply the voltage with the polarity reversed your GPS will most likely suffer damage.
My GPS has a crossover adaptor with a jack to connect an antenna.
I always used the adaptor because it extends the length of the power cord.
The consequence of bending the GPS mini jack from dropping the unit was that the contacts in the units usb mini jack and the usb crossover adaptor plug were damaged. The red and black wires are the positive and negative connections for the 5 volt power from the dc to dc car adaptor.
Or Installing a New USB Connector Instead of Hardwiring
After soldering the power leads to the GPS I concluded that I should be able to replace the mini usb jack even though I don't have a microscope to work under.
I bought two different connectors in the event that one of them didn't work out. I used the Molex Part No: 54819-0572 Mini USB Type B Connector RCPT 5POS SMD.
In this photo I am attaching the front usb mini jack shell tabs to
the circuit board.
The circuit board pads were ripped up when removing the shell so I used some copper wire to bridge to the remaining copper.
The GPS is ready to be closed up. The speaker came out of the plastic housing when I took the unit apart. I pressed it back into the housing and applied some super glue gel in a couple of places around the speaker.
In this photo I'm powering the GPS through the automotive power adaptor applying 13.8 volts from my test bench power supply to the power adaptor.