Unfortunately it seems as though the motherboard may have suffered some damage.
Did you disconnect the battery from the motherboard before you started replacing the display assembly? Not as per the incorrect display guide, but as per the Dell Inspiron 15-5567 Battery Replacement guide?
You will need to use the motherboard schematics to diagnose what the problem is.
If you decide to do this then please check that the laptop’s motherboard board number (found printed on the motherboard itself) is the same as in the link provided i.e. BAL20 LA-D801P-REV1.00 A00 to ensure that they are the correct ones for the motherboard. If it is not the same board number as your motherboard, search online for (insert motherboard board number) schematic to hopefully find it
You will need to have a DMM (digital multimeter) and know how to use it and also how to read schematic diagrams to diagnose what is wrong.
If this seems too daunting then contact a reputable laptop repair service and ask for a quote for the repair. The alternative is to buy a replacement motherboard and install it in the laptop. Search online for Dell i5 5567 motherboard to find suppliers.
For future reference and it is meant with the best intentions, always remove or disconnect the power source from an electronic device, be it a power cord or a battery or both, and verify that it is disconnected, before working on the device. In the case of an internal battery as soon as it can be safely accessed. Once the power has been disconnected then commence the repair. Then only reconnect the power source as late as possible in the re-assembly procedure or after the repair is complete to avoid any electrical problems occurring due to accidental contact with the components when using tools etc.