Hi I have a Holux 236 paired with my M3100 PDA. All works well, except for a problem with in-car charging. The Holux charges fine in the car with the supplied mini-USB connector. The Holux charger does not though charge the M3100. I bought a mini-USB Y cable to charge both. It charges the M3100 fine (through either connector) but hangs the Holux so I have to take the battery out to reboot. There seem to be two possible reasons: I found the following on a forum, "We measured voltage coming from different charging cables. Both USB-miniUSB cables for our two GPS's has the same output (pin 1 +5V, pin 5 ground). Both RJ11-miniUSB cables (for our two PDA cradles) also has the same output, but the 5V and ground were opposite (pin 1 ground, pin 5 +5V). It explains why cable didn't work with Holux GPS's and worked with our PDA. It looks like the PDA might have a built-in rectifier so you can charge it either way, but Holux model doesn't." I am not sure about that. I think the problem may be to do with pin 2. The Holux spec notes: A/1 = GND B/2 = NC C/3 = +DATA D/4 = -DATA E/5 = +5v I think the PDA cables have pins 1 & 2 linked - telling the phone "This is not a USB power supply" so the phone charges the battery at its maximum safe rate. I think grounding pin 2 causes a problem for the Holux, despite it noting pin 2 "n/c". I have thought of trying to disconnect pin 2 inside the Holux to see if it fixes it but it would not be easy without risking damage. Can you throw any light on this? Thanks in anticipation Michael
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