Won't boot. Got POST Failure

That is a frustrating spot to be in, especially since you’ve already performed the "standard" fixes like reseating RAM and pulling the CMOS battery.

Since the CapsLock and FnLock lights are static but the screen is black and the power button is unresponsive, your laptop is likely stuck in a "zombie" state where the motherboard is receiving power but failing to complete its Power-On Self-Test (POST).

Here is a breakdown of what you should try next, moving from simple logic resets to potential hardware culprits.

Even though you've tried holding the power button, let's try a more clinical version to ensure all capacitors are fully discharged.

• Disconnect everything: Unplug the AC adapter, the main internal battery, and the CMOS (coin) battery again.
• The Hold: Press and hold the power button for 60 full seconds.
• The Test: Plug in only the AC adapter (leave the batteries disconnected). Try to turn it on. If it boots, your battery or a static charge was the culprit.

It is possible the laptop is posting, but the internal display or the ribbon cable has failed.

• Connect the laptop to an external monitor or TV via HDMI.
• If you see the Lenovo logo on the TV, your laptop screen or the eDP cable (the connector between the motherboard and screen) is the issue.

Sometimes a failing peripheral prevents POST.

• Strip it down: Disconnect the SSD/Hard Drive, the Wi-Fi card, and any USB devices.
• RAM Swap: If you have a stick of RAM in the removable slot, take it out entirely and try to boot using only the soldered-on memory (this model usually has 4GB or 8GB soldered). If the removable stick is faulty, it can prevent the boot process.

Since your keyboard lights are responding, the BIOS might be corrupted but still partially functional.

• Turn the laptop off (you may need to disconnect the battery to force it off).
• Hold Fn + R. While holding them, plug in the power cable and press the Power button.
• If the fans spin up loudly or the screen flashes, the laptop is entering a BIOS recovery mode.

If none of the above works, we have to look at the "unfixable" options:

• Corrupted BIOS Chip: The firmware on the SPI chip may be physically corrupted. This usually requires a professional with a CH341A programmer to re-flash the chip.
• CPU/GPU Failure: On the IdeaPad 3-14ALC6, the Ryzen processor is soldered. If the power rail for the APU has failed, the board will stay in that "lights on, nobody home" state.

Would you like me to help you find the specific hardware maintenance manual for your 14ALC6 so you can identify exactly which cables to unplug for a deep reset?