I dont really know how to describe it. The arduino gives the host shield enough power to light up the leds of my mouse / keyboard, but not enough to power inputs (mouse movement). I soldered it already, still having the issue. Should I resolder? I am using an arduino leonardo r3.
@xradars, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with your project; see About the Installation & Troubleshooting category.
Can you provide some details? Which host shield (link/url please)? How do you power your setup, USB or external power supply via e.g. the barrel? Can you show a reasonably sized photo (around 300 kB) of your setup.
The concept of an Arduino board "giving the host shield power" is singularly misguided.
Most projects require a proper 5 V regulated supply, which you can connect to the "5V" pin except when it is connected to a PC via the USB socket.
You may or may not be able to supply sufficient 5 V through the USB socket.
Mind you, you do need to fully describe your setup. 
Im not home so i cant provide a photo.
I am using (https://www.amazon.com/HiLetgo-Shield-Arduino-Support-Android/dp/B01MTU9OLM/ref=mp_s_a_1_4?dchild=1&keywords=usb+host+shield+arduino+uno&qid=1626995375&sprefix=usb+host+shield+arduino&sr=8-4)
I use the usb that came with my arduino leonardo r3.
Sorry if some of what i say is dumb, i started with arduino a few days ago.
Because there is a fuse inline with Leonardo's USB port, this drops some voltage. It drops more voltage then more current you draw from it. There is also a transistor that drops a small amount of voltage. Then you have your keyboard cable. If you supply 9V to 12V on your Leonardo's barrel connector, you can better supply power to the keyboard.
I don't see a benefit for that; it would make use of the onboard voltage regulator which more than likely is a worse solution due to power dissipation by the onboard voltage regulator. It's nowhere specified how much power that voltage regulator can actually dissipate (and for me the calculations would be difficult).
If OP wants to try, I suggest to use a 9V supply and not a 12V.
I was hinting at that very strongly. Was I somehow too subtle?
Possibly 
@liuzengqiang seemed to have other thoughts 
I decided to use a 9v barrel connector and it did not help, im assuming the solder bridge is weak. I am gonna re solder and go from there.
Most arduino and clones have OK voltage regulators except for arduino srl. They are how if supplied with 12V. I've read spec sheet for at least one of these to be750mA at 5V. I don't know what 9V source the OP tried. 9V battery or an adapter with what current rating?
I tried a 9v and 12v adapter, exact same issue /:
Well, as i was soldering i dropped the host shield and 2 pins snapped off. Ill buy another one and see if it works
I remember one of the host shields I bought had some wrong solder jumpers soldered on. I had to desolder them. Could you post a clear photo of the top of your shield and bottom to show the damaged pins. Those pins may or may not matter.
Did you happen to notice in the spec sheet, the thermal parameters?
Was that really the point, trying to nitpick on my comment? Do you have an OP to help?
As so often happens, we are discussing the possibility of an insufficient power supply to the board - in this case a Leonardo - and a USB Host shield.
The simple fact of the matter is that the largely decorative linear regulator on the older Arduino boards has minimal heatsinking from small areas of copper surrounding. Whatever the regulator's datasheet may suggest as its maximum current capability is entirely subject to adequate heatsinking which these boards do not provide, so that maximum current specification is actually completely irrelevant.
It is therefore appropriate to caution against attempting to power via the "barrel jack" or "Vin" for serious applications. It is not a quibble, it is the reality.
The more recent Arduino designs do use modern regulator technologies and may be practically powered by a higher voltage.
i already stated that i have tried many other ways of powering it, meaning power might not be the issue. anyways, i managed to get my host shield back to normal, resoldered, still having the same issue. It doesnt power anything (ex. keyboard inputs, mouse inputs, controller inputs) but still lights up the device, or signals that the device is powered in some way.
I believe I was genuinely trying to help you but if you don't wish to share some photos to let me see your situation, I won't be of much use to you. Farewell.
Mexican standoff. 
