lenovo t420 laptop does not turn on

Well, I have the thinkpad t420, it turns on for 20 seconds, it starts Windows and it turns off and the two orange LEDs stay blinking and it doesn't turn on again, so I have to download it to turn it on again, I tried the memories but the LED error orange color flashing, I don't know why,

 

Hello,
Trust you are doing well, apart from the laptop problem that you have.

As per my knowledge, the orange lights indicate some issue with the power not received to the laptop or not providing enough power to the laptop. Mainly, it is caused by the battery of the laptop.
Please try removing the laptop battery and turn it on through direct power cable. Please make sure the laptop is not connected to a high power as it might damage the inner components of the laptop.

If the laptop is working fine with only power adapter (no battery installed), it might be the time for replacing the laptop battery.
If the same issue is occurred, it might be not enough power receiving to the laptop, try different power outlets and if possible, try a different power adapter of same voltage or a bit higher voltage.

Incase the issue still persists, I have no idea whats the problem with the laptop. It might be the time to check it with the laptop service center.

I hope this helps. Have a great day ahead!

 

You say that the LEDs stay blinking, do the fans remain on?