# Raspberry Pi 3b+ Won't Boot / Won't See Enviro PHAT on i2c **URL:** \ **Category:** Support\ **Created:** [August 28, 2018, 10:13pm UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528 "2018-08-28T22:13:15Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![chrisd](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@chrisd](https://forums.pimoroni.com/u/chrisd)\ **Post date:** [August 28, 2018, 10:13pm UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528/1 "2018-08-28T22:13:15Z")
Hi there; so i’m trying to get my enviro phat working but i’m experiencing something really odd and my google foo has failed me, please help :-) I’ve soldered it (see below) and i think it’s ok, i’ve gone over it to make sure and all seems well, i’ve also gone over it with a multimeter and again all seems to be ok; no shorts that i could detect. What’s wierd is plug it in one way around and my Pi refuses to start, no activity will register at all, red light just stays solid: [https://youtu.be/HTWrkmoV6Ts](https://youtu.be/HTWrkmoV6Ts) Plug it the other way around and at least the Pi will start _but_ then it cannot talk to the phat: (video of it starting, below is screenshot of the phat not responding) [https://youtu.be/9bPzsutlQLA](https://youtu.be/9bPzsutlQLA) I’ve no idea what to prod next, is it a duff board or a duff user; any help much appreciated! Thanks Christopher p.s. sorry new users can only post one image and 2 links, sorry for the dbox links :( My Pi Is a Pi 3B+ running Raspbian on a 32GB SD card. I’ve tested the camera, all working great! I’ve added: Enviro pHAT -Temp/Pressure/Light/Motion Sensor MMP-1034 Raspberry Pi Camera Board - V2 (8MP) Raspberry Pi Camera Board Replacement Cable - 610mm 40 Pin GPIO Male to Female Ribbon Cable - 150mm ModMyPi Mini Camera Stand (No Lens) Picture of soldering: ![Soldering](https://us1.discourse-cdn.com/flex016/uploads/pimoroni/original/2X/5/5e0ea506c539e368ed25d7e2d1e6e919e933c1df.jpeg) Screenshot of error; text below: ``` chrisd@raspberrypi:~/Pimoroni/envirophat/examples $ i2cdetect 1 WARNING! This program can confuse your I2C bus, cause data loss and worse! I will probe file /dev/i2c-1. I will probe address range 0x03-0x77. Continue? [Y/n] y 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- chrisd@raspberrypi:~/Pimoroni/envirophat/examples $ ./temperature.py Light the LEDs upon temperature increase. Press Ctrl+C to exit. Traceback (most recent call last): File "./temperature.py", line 18, in temperature = weather.temperature() File "/usr/lib/python2.7/dist-packages/envirophat/bmp280.py", line 134, in temperature self.update() File "/usr/lib/python2.7/dist-packages/envirophat/bmp280.py", line 169, in update if self._read_byte(REGISTER_CHIPID) == 0x58: # check sensor id 0x58=BMP280 File "/usr/lib/python2.7/dist-packages/envirophat/bmp280.py", line 116, in _read_byte return self.i2c_bus.read_byte_data(self.addr, register) IOError: [Errno 121] Remote I/O error chrisd@raspberrypi:~/Pimoroni/envirophat/examples $ ``` [![](https://us1.discourse-cdn.com/flex016/uploads/pimoroni/original/2X/c/c2b4a244529714290a50f4012fef06e8adcf13b2.png) ](https://dl.dropboxusercontent.com/s/n0hx6a4z55m179a/Screen%20Shot%202018-08-28%20at%2022.56.51.png?dl=0) ---
**Author:** ![JennyHart](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/jennyhart/32/459_2.png) [@JennyHart](https://forums.pimoroni.com/u/JennyHart)\ **Post date:** [August 29, 2018, 6:56am UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528/2 "2018-08-29T06:56:21Z")
You’ve soldered the header to the wrong side of the phat. I suspect that with the cable plugged in one way there’s a combination of pins the Pi doesn’t like and so won’t boot. The other way around the pins are still plugged in the wrong way so it still doesn’t work (the i2c pins on the board aren’t connecting to the right GPIO pins). Hard to tell exactly what orientation you have in the video. I’m trying to do the mental gymnastics to see if there’s an orientation that would work and I’m failing… Also check the header on the cable at either end isn’t off-set by a pair of pins (it can happen). Ther’s a good guide here [https://learn.pimoroni.com/tutorial/sandyj/getting-started-with-enviro-phat](https://learn.pimoroni.com/tutorial/sandyj/getting-started-with-enviro-phat) that shows the correct orientation of the soldered header. ---
**Author:** ![chrisd](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@chrisd](https://forums.pimoroni.com/u/chrisd)\ **Post date:** [August 29, 2018, 7:03am UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528/3 "2018-08-29T07:03:01Z")
Oh my goodness what a plonker!!! Will have to get my handy solder sucker out. Thank you :-) ---
**Author:** ![chrisd](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@chrisd](https://forums.pimoroni.com/u/chrisd)\ **Post date:** [August 29, 2018, 9:41am UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528/4 "2018-08-29T09:41:46Z")
Just to confirm that i’ve re-soldered it on the right way around and all is now working 100%; thanks so much @JennyHart ---
**Author:** ![JennyHart](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/jennyhart/32/459_2.png) [@JennyHart](https://forums.pimoroni.com/u/JennyHart)\ **Post date:** [August 29, 2018, 9:55am UTC](https://forums.pimoroni.com/t/raspberry-pi-3b-wont-boot-wont-see-enviro-phat-on-i2c/8528/5 "2018-08-29T09:55:33Z")
Excellent news! Glad to be of help.