Server Powersupply mod


Staff member
Photo on 4-9-23 at 12.39 pm.jpg

The boards have arrived !
It is very important you hold your tongue at the correct angle while aligning the PCB onto the USB socket pins ;)
I have not added the current setting Rs yet, just a 1K resistor for the LED.
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Staff member

Worked out pretty good, I got 4 new panels done + one I had already wired. It helps to have something plugged into the USB connector when soldering the power and data pins on the USB connector. Also I lightly filed out the slot to provide a bit more clearance.

I'm still confused by the resistors, I can understand the device end needing resistors to tell the charger how much current it can handle, but
why does the charger end ( which, in our case has no ability to change current delivered need resistors? )

It looks like the dedicated charger option just shorts out D+ D- maybe that's the option to use for this?

What were you thinking of using for resistor values?


New member
TLDR: Max 200Ohm Data+ and Data-

be careful not to mix up port and devices.
as with most of the nightmare it can be with USB it depends on what spec you are trying to achieve and the situation is not so straight forward as there is spec by usb with options and also other idea by others. but basically USB trys to be backward friendly so by default usb is typically only 500mA. If you want more you need to tell the charger that it is ok to give you more, else it should cut power, also a way to check what is pluged in. (depending on spec), and lets the device know it it can draw more pwr. and we will stay well alway from the USB C power stuff as that is just a whole other level of fun.

The best basic thing here to adopt is the BC1.2 DCP (dedicated charging port)

where RDCP = Max 200 Ohms.

else you implement the other propriety ports since you have 4.


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Staff member
R17 is a 1K resistor for a power LED if you want to run it from the 5V supply.
The other Rs, I have not added as yet.