Inspiron 14 Plus 7420 sudden no power / no post - only amber LED

Hello,

I have a Dell Inspiron 14 Plus 7420 that suddenly stopped turning on.

Until yesterday, it was working normally. The battery appeared to be in good health, with no previous battery or charging problems.

Current symptoms:

• No fan noise, No keyboard backlight
• No Dell logo
• No screen activity
• No normal charging LED response
• The laptop shows a solid amber/orange LED only while the power button is pressed. As soon as I release the power button, the LED turns off
• The Dell barrel charger is healthy, and I also tested USB-C power, but the laptop still did not charge or boot

Already tried:

• 20-second hard reset
• RTC reset attempt with charger connected, holding power for 30–35 seconds
• M-BIST test
• Ctrl + Esc attempt to trigger the BIOS Recovery screen

None of these produced a Dell logo, fan activity, keyboard light, BIOS Recovery screen, or diagnostic blink code.

I found this Dell KB, which explicitly lists Inspiron 14 Plus 7420 under models affected by "No Power / No POST failure modes", But it doesn't instruct on what to do if this failure mode already happened:

https://www.dell.com/support/kbdoc/en-us/000211987/bios-update-helps-prevent-no-power-and-no-post-failure-modes

My question is: what should I do now?

I would appreciate any advice or relevant experience. Thank you in advance for your time!