Can't update HP Probook 445 R G6 BIOS or Change RAM

Recently bought HP Probook 445 R G6 - AMD Ryzen 5 with 8 GB RAM

1. Working fine with Windows 10 with little high HEAT generation without power adaptor.

2. While updating BIOS without POWER ADAPTOR - LAPTOP went in COMA state.

3. Tried replacing RAM, HARD Reset etc.

Windows Key + B,

Windows Key + V,

Shift + CTRL+ Windows Key + B

There is no Visual response.

4. There are 2 Long Beep and 1 Short Beep

5. While Updating BIOS via USB stick - HP Firmware Update and Recovery doesn't recognize USB Drive which is shown in Windows 10 Explorer. Tried different USB with different Ports.

Any Solution