🇬🇧 🇪🇸 Bottom module Voltage measurement. Medida del voltaje del módulo inferior

I’m having power issues with my FP2:

  • Battery is not charging
  • Fairphone power loop (without battery) doesn’t happen.
    I have no friend with a fairphone and neither would like to buy a bottom module if it’s not the problem.
    My idea is to find out where the problem is with a tester / polimeter wich I can measure the power supply with and see if the problem is the battery or a not working power module. The only thing I need is the bottom module`s pinout with the correct Voltage / Current as well as the battery pins (where the phone takes from and gives power to the battery) so I can measure and compare.

Can anybody help?
I would appreciate a topic llink for my problem as well.

Estoy teniendo problemas de carga con mi FP2:

  • La batería no carga
  • El reinicio que se supone que el FP2 debe hacer al cargarlo sin batería, no ocurre
    No conozco a nadie que tenga un Fairphone 2 y no quisiera comprar el módulo inferior sin saber si es el causante del problema.
    Lo que pretendo es averiguar dónde está el problema con un polímetro. Medir los pines del módulo inferior y los que hacen contacto con la batería para la carga y el funcionamiento del móvil. Lo único que necesito es el pineado correcto de voltaje y corriente con el que pueda comparar mis mediciones.
    ¿Alguien me puede ayudar?
    También agradecería la referencia a un hilo que trate este problema.
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Where in Spain are you located? There are Fairphone Angels (see #fairphoneangels) in Barcelona and the Basque Country who can test modules for you.

Also pinging @Leo_TheCrafter who might know pinouts.

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By the way, I just remember I have a spare bottom module whose microphone is broken. I’m in San Sebastián, Basque Country at the moment. In case you don’t live near me or near any of the Angels, I am able to post that module to you so you can test whether your phone charges.


The pinout is
Mic Data I GND I Mic VCC I GND I Speaker L I Speaker R

But be aware that a missing voltage can be caused by :

  • Bad connector (most of the cases)

  • Bad filter

  • Shorted capacitor


@AlbertJP, @Leo_TheCrafter
You are awesome. Thank you very much for your response and help.

I live in Jerez de la Frontera, Cádiz. A bit far from the Basque Country or Catalonia. But I could send my module to be tested anyway.
AlbertJP, I am willing to pay for your module shipping and back, of course, so I can test it on my phone.

Leo_theCrafter, Is it too much to ask if you could tell me the supposed voltage on the pinout?

Again, thanks both very much.

PS: I have been to San Sebastián many times. Beautiful City.

@AlbertJP, @Leo_TheCrafter
Sois increibles. Gracias por vuestra respuesta y ayuda.
Vivo en Jerez de la Frontera, Cádiz. Queda un poco lejos de País Vasco o Cataluña pero, aún así, puedo enviar mi módulo para que lo testeen.
AlbertJP. Por supuesto que pagaré por el envío de ida y vuelta del módulo inferior si estás dispuesto a prestármelo para probarlo en mi móvil.

Leo_theCrafter ¿es mucho pedir si pudieras decirme el supuesto voltaje del pineado?

De nuevo, muchas gracias a ambos.

PD: He estado muchas veces en San Sebastián. Es una ciudad preciosa.

It should be 5 or 5.2 or so volts on VBus. Not that this pinout is only correct if the USB jack is on the bottom.

Yes, I supposed it was USB average voltage. Tank you, again.

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I just got reply from Fairphone support. They say it’s the bottom module.
I’m going to buy a new one. The “doesn’t loop” thing is very illuminating.

Anyway thank you for your help.

Acabo de recibir respuesta del soporte técnico de Fairphone. Dicen que es el módulo. inferior. Voy a comprar uno nuevo. El tema del “no reinicio” es muy esclarecedor.
En cualquier caso, gracias por vuestra ayuda.

FYI The voltage measures I got from the bottom module were:

2,7V | 2,1V

I don’t know for sure if 4,8V are enough for the phone and a loading battery but that’s all I have. I only hope the new bottom module will solve this problem. If not, i’m afraid I bought another programmed obsollescence gadget.

In order to charge you need a higher voltage from your charger than the battery’s own 3.8V. I think 4.8V should be sufficient.

However, you are measuring voltage on the data lines now. USB+ and USB- are data lines, not charging lines. You need the voltage between VBUS and GND.

If you’re measuring on USB+/USB- when connecting a charger, you are just measuring the resistor in the charger which indicates its capabilities. D+=2.8V and D-=2.0V (or close to that) means you have a 2A charger (which is nice).
(Source: https://en.wikipedia.org/wiki/USB_hardware#USB_Battery_Charging)


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