T15 gen 2 won't turn on - blinking lights - dead mobo?

[iamdmc]

After not using my T15 gen 2 for a few weeks I finally tried to turn it back on. I tried plugging in the laptop in case it was a dead battery, but even after a few hours on charge it did not power on. I've tried the 'reset' button on the bottom of the laptop (with and without the battery and CMOS battery connected) to no avail. I've tried removing and re-seating memory, SSDs, etc. No peripherals plugged in.

Strangely, it did turn on once when I swapped in a T14 gen 2 battery (to test if the battery was faulty) but after shutting down again it didn't turn on again.

Behaviour 1:
When I plug in the charger, I get blinking lights (on/off every 1-2 seconds) on the lid (the i), the power button, and the LED next to the USB C charging plug. It's not the same blinking behaviour as 'sleep' and the T15 remains unresponsive to power button presses.

Behaviour 2:
Sometimes, I can press the power button and get the fan to ramp up, followed by 3 flashes from the power button LED, then the laptop turns off again. Press the power button again - same thing happens

either way NO BOOT - no beeps, nothing

I can't for the life of me understand what it could be... bad motherboard maybe?

Has anyone had any similar experience or have any idea what this could be?

[RealBlackStuff]

Bad power supply?
Bad USB C port?

[iamdmc]

Bad power supply?
Bad USB C port?

Thanks for your reply

I've tried several Lenovo usb c 65W chargers on several plugs around my house and no difference

Either usb c port seems to charge the battery, as it reads as 100% when plugged into my other laptop. If anything I don't think it's the charge circuit

[mikemex]

Open it up, disconnect the battery, hit the power button for a few seconds, and re-attach the battery. That should drain the capacitors and reset the system. If it doesn't power on after that, send it to warranty.

Also, my X1C4 has a small hole in the base to reset the BIOS to factory defaults. Does the T15 Gen 2 have that?

[iamdmc]

Open it up, disconnect the battery, hit the power button for a few seconds, and re-attach the battery. That should drain the capacitors and reset the system. If it doesn't power on after that, send it to warranty.

Also, my X1C4 has a small hole in the base to reset the BIOS to factory defaults. Does the T15 Gen 2 have that?

Thanks for the reply. I jiggered it just right (no idea how) that it started working again