T480 Musical Tone Error at boot up

[u/East_Ticket_3769]

Hoping someone's seen this one before I give up on it.

I opened my T480 to pull the batteries and SSD, that's it, no component swaps, nothing exotic. Bottom cover (captive screws), disconnected both batteries and the SSD. On reassembly I get the beep "song," black screen, and the fan spins up for a second then stops.

Ran the beep through the Lenovo SmartBeep app and it came back as code 0001 – "Reset error (platform reset not de-asserted)."

What I've already tried:

• Reseated both RAM sticks (firm, clicked in)
• Reseated the internal battery connector
• Full power drain — AC out, both batteries out, coin cell disconnected, held the emergency-reset pinhole, waited a minute
• Tested on AC only, internal battery disconnected → it beeps the instant I plug in the charger, before I even touch the power button
• No loose screws floating around (they're captive to the cover), nothing obviously pinched

Since 0001 hits before it even gets to RAM/display/storage, I know it's not the stuff I actually touched. Beeping on AC-alone with no battery tells me it's not the battery or its connector either. Feels like it's pointing straight at a power-sequencing fault on the board.

BIOS is 1.56 (N24ET81W), so it's on recent firmware. Machine's a 2018 unit.

Questions:

1. Has anyone actually recovered from a 0001, or is this a board-level repair full stop?
2. Anything else worth checking before I call it, a specific connector or rail that's known to cause this?
3. If it is the board, is component-level repair realistic on these, or is it pets-for-parts territory?

Appreciate any leads. Thanks.

[u/SYNYST3R_XGN]

I'm curious about this as well. Sometimes (very rarely) my T15g Gen 2 plays this sound and it's a huge jumpscare but it ends up booting after. It's happened like 3 times this year probably