Welcome to the forums!
Have you tried removing the battery for a few minutes and then reinserting it?
When the phone is connected to the charger do you see a battery graphic showing the battery level and charging activity?
Here's an overview of Recovery mode and Download mode:
- you use Recovery mode to clear the system cache and to Factory Reset
- you use Download (aka Odin) mode (showing the Android guy) to load/reload firmware
- the key sequences to enter both modes are very similar, and they are timing dependent so it may take a few tries to get it working
-- Recovery = Volume Up + Home + Power
-- Download = Volume Down + Home + Power
- for either, you start with the phone completely off
- press and hold the required keys simultaneously, and release them all when you see the swirling logo (not the static white text)
Try Recovery mode first (use the Volume rockers to navigate; use the Power button to select) and if it boots into this mode just clear the cache and then restart. If the phone doesn't boot normally then try Download mode - if that works let us know and we'll go on to the next step.
Sent from my rooted, debloated, deodexed Sinclair ZX-80 running CM -0.001 using Tapatalk