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On the original model b it was possible to wire power to the tp1 and tp2 (which ran through the fuse and was protected?) I am upgrading my 3d printer to run with a b+ but the b+ does not have the same tp pins. Is there a different way to wire power to the b+ that doesn't use the gpio header or micro usb?

Edit: i am using a 12v to 5v3a to get power to the pi if this helps.

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I know you don't want to but I'd still use the expansion header. Perhaps wire to the underside of the board so the pins are still usable.

If you really want to wire in a similar fashion to TP1/TP2 you could try the test points.

PP1 5V from micro-USB
PP2 5V from micro-USB
PP3 GND
PP4 GND
PP5 GND
PP6 GND
PP7 5V after polyfuse

Sorry, don't remember where I found the test point list. Probably from a post on the raspberrypi.org forum.

There is a limited schematic for the B+.

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  • Thanks. I ended up wiring my 12v to 5v3a power supply up to a 2pin header and just plugged it into the gpio.
    – jgetrost
    Jun 16, 2015 at 11:48
  • That's one of the methods I use. 12V supply to 5V UBEC to 2-pin header fitted over pins 4 and 6.
    – joan
    Jun 16, 2015 at 11:50
  • Yep. Im pretty sure my step down is regulated, but the fuse is 2a on the pi so it is possible I could blow it? But hopefully everything will be ok. Thanks for your help.
    – jgetrost
    Jun 16, 2015 at 11:51
  • @joan : 5V/GND over pins 4/6 will bypass the board protection, right? (Although a 5V UBEC should be safe enough...) What do you think?
    – dentex
    Mar 29, 2017 at 7:23
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    @dentex Yes, 4/6 bypass the polyfuse over current protection and the (little) over voltage protection. I've powered Pis for years like this without problem.
    – joan
    Mar 29, 2017 at 7:29

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