USB slots not working

Hi,

What is the full model number of the laptop?

Did you remove or disconnect the main battery from the laptop before attempting to repair the USB port?

Even though the laptop was off there is still power available at various places on the motherboard. The laptop's Power button is not a power isolating button. It merely signals the BIOS as to the intentions of the user. Think of the laptop as being in an extremely low power state rather than being totally switched off, when it is off.

If not, then you may have damaged the USB power supply circuit or perhaps the USB controller.

Plug a USB device into the ports just to see if power is being supplied by the port even though the device is not being recognized e.g. a mobile phone - shows charging or a USB mouse - laser light turns on

You will have to open the laptop and inspect for any obvious damage. It may be easier if you open it up and then find the motherboard’s “board number” (printed on motherboard itself) and use that number to hopefully find the schematics for the motherboard as these will help you to know what board components need to be checked in case there is nothing visibly obvious.