PC not switching on

@gamarielmavende blinking Caps Lock and charging LEDs are indicating a hardware failure or a power delivery issue which prevents the laptop from passing the POST (Power-On Self-Test) and thus does not power on. Let us know if there is a pattern to the blinking.

Start off by trying a hard reset. Disconnect the charger and all external devices (USB drives, mice) as well as the battery. Press and hold the power button down for a full 30-45 seconds to drain residual flea power from the capacitors. After that plug only the charger back in and try to turn it on.

If it still does not turn on, you need to check and see where your motherboard even gets power. For that of course, you need to open it up. Post Some good pictures of what you see. That way we can see what you see. Of course, you may also have to consider replacing the battery. A depleted battery can no longer be charged. However, it should not prevent your computer from coming on, if it is connected to the AC adapter.

It is also possible that this is a bad RAM module. So remove the RAM, clean the contacts with a pencil eraser. Do it gentle so as to not destroy the module. Replace it and restart. If you have more than one module, remove it and just leave one connected.

After that we ill need to know what pattern the LEDs are blinking in. To work on your laptop use the HP ProBook 640 G4 Maintenance And Service Guide