Keyboard drawing only 0.1A from charger

[qwazix]

As the title says, the keyboard is only drawing tiny amounts of power, regardless if it has a phone in it, if it's on, and of the constant current sysfs setting.

I did plug the phone in while docked before I read the warning, did I fry the charging chip?

[PakoSt]

Check in the #pinephone channel.



iirc this is due to the D1 diode that was added with the April batch. I did make a small short on mine to go around it but I would definitely check on the channel first.

Spoiler:

Here is my... attempt at the short
Photo of the questionable solder job

Quoting megi here:

[i]<megi1>: CalcProgrammer1 discovered that protection diode was placed at VBUS of KB input, which prevents charging, instead of at phone's VBUS outptut, which would maybe protect the kb boost output from damage when plugging in something into a phone's type-c port
so, no protection, and crippled charging ability

[I] <megi1> easy HW fix is to short the diode

Still, before doing anything of the sort - confirm that this is the cause of your trouble!

[magdesign]

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@maintainer of this forum: does it make sense to have a Accessories category under pinephone and one under pinephonepro ?
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To get rid of the 0.1A issue, you need to shorten diode D1.

!!! Please do this only if you are used on handling electronics and soldering, if not, its better to visit a specialized electronics repair shop or ask someone who is used to do stuff like this !!!

For this you need to do following steps:

1.)  Open the keyboard case.
       Starting from the edge with the little notch, use your fingernails or a guitar plank.
      The clips behind the hinge are inaccessible so open that side as last.
  
    


2.) When the case is open, unscrew the pcb and disconnect the power cables so there is no power on the PCB.



3.) Spot the diode D1, see the red circle:



4.) Solder a tiny cable or thin electronic wire to bridge it, like this:



make sure you really only bridge D1 and you do not touch anything else on the PCB with the soldering iron!

5.) Connect all the connectors back and reassemble the Keyboard.

6.) Test if everything is working as expected and post below if you have success and maybe also some tricks :-)



Thanks to all the people on the Pinephone chat and for the pictures shared by @megi and @Pak0st

[PakoSt]

Those guitar picks really did a number when you opened the unit. Will post a pic tomorrow as of how mine turned out.



I used the following set from iFixit: https://store.ifixit.co.uk/products/pryi...assortment

In particular - the thin plastic cards and the spudger. My goal was to avoid wiggling the spudger too much so that there won't be much pressure directly on the edge. It was more of a... sliding motion with the flat part instead of straight up stabbing.



I did start with Jimmy (metal prying tool looking like a dull knife) but the deformation on the edge was a tad too much for my liking. It should show in the pics I will post tomorrow.



The guitar picks in comparison look to have been noticeably more aggressive. I'm not sure how effective my "finger nail filing" of the edge would be in this case.

[Update] Pictures bellow:
You can see where I started with the metal tool and where I've left a mark:
   

Next was the USB-C port side and you can see where I was still adjusting on how to use the spudger. Right above the USB-C port you can see where I've stabbed it before switching entirely to sliding motion:
   

Everything else was a lot easier once the technique was in place. The marks on the side without ports are really small compared to the start:
   

[joe_w]

****************************************************************************************************************************************************
@maintainer of this forum: does it make sense to have a Accessories category under pinephone and one under pinephonepro ?
****************************************************************************************************************************************************

To get rid of the 0.1A issue, you need to shorten diode D1.

!!! Please do this only if you are used on handling electronics and soldering, if not, its better to visit a specialized electronics repair shop or ask someone who is used to do stuff like this !!!

For this you need to do following steps:

1.)  Open the keyboard case.
       Starting from the edge with the little notch, use your fingernails or a guitar plank.
      The clips behind the hinge are inaccessible so open that side as last.
  
    


2.) When the case is open, unscrew the pcb and disconnect the power cables so there is no power on the PCB.



3.) Spot the diode D1, see the red circle:



4.) Solder a tiny cable or thin electronic wire to bridge it, like this:



make sure you really only bridge D1 and you do not touch anything else on the PCB with the soldering iron!

5.) Connect all the connectors back and reassemble the Keyboard.

6.) Test if everything is working as expected and post below if you have success and maybe also some tricks :-)



Thanks to all the people on the Pinephone chat and for the pictures shared by @megi and @Pak0st

Thanks for the post.  After shorting D1, my charging current increased from 260 mA to 1.75 amps.

[magdesign]

Left: PCB from factory end of July 2022, with soldered diode
Right: PCB from my first batch keyboard without diode

[d4s]

Thanks for the manual! Right after the removing the diode and soldering contacts, my keyboard is able to charge the phone and itself in the same time. Much appreciated!

[ClairelyClaire]

Has anyone tried replacing the diode with a higher-quality one, or checking to make sure the ballast resistor in the circuit is the right size? Removing the diode AFAIK removes at least one bit of overvoltage protection, which might be what fried it in the first place.