D-/D+ pins > 2v
Moderators: adafruit_support_bill, adafruit

D-/D+ pins > 2v

by russtoku on Sat Feb 16, 2013 8:08 pm


I soldered up two V3 minties and notice that the D-/D+ pins are 2.96 v instead closer to 2.0 v. Other minties I've soldered came in at 1.93 v with 4.96 v for the USB power. I soldered the USB connector on to one of the recent minties and it won't charge my iPhone 3G. Other minties I've solders did charge my 3G. I've attached some photos of the boards. Suggestions besides checking the solder joints?

boost-02-bottom-a.jpg (216.19 KiB) Viewed 1461 times
boost-01-bottom-a.jpg (221.77 KiB) Viewed 1461 times
boost-01-top-a.jpg (207.47 KiB) Viewed 1461 times
Posts: 2
Joined: Sat Nov 24, 2012 4:22 pm

Re: D-/D+ pins > 2v

by adafruit_support_rick on Sun Feb 17, 2013 2:52 pm

What voltage are you seeing between USB pins 1 and 4? Should be 5V.

You might also want to check the batteries in your meter, and/or check your meter against a known reference.

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Re: D-/D+ pins > 2v

by russtoku on Mon May 06, 2013 3:51 am

I haven't been able to work on this for a while but the voltage between pins 1 and 4 is 5.0. I've rechecked the solder joints and the D- and D+ pins now have 1.94 when using 2 AA Duracell Alkalline batteries (1.4 and 1.5v). However, inspite of the voltages being the proper values, my iPhone 3G doesn't start charging. Another Minty Boost has the same voltages and does start charging my iPhone 3G.

Now, I'm puzzled. Any suggestions would be appreciated.

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Joined: Sat Nov 24, 2012 4:22 pm

Re: D-/D+ pins > 2v

by adafruit_support_bill on Mon May 06, 2013 6:54 am

Make sure the batteries are fresh. Tired batteries (especially alkalines) will fade quickly under load.

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