SOLVED: Lenovo Flex 3 Flashing Power Light But Will Not Power Up

If you have a Lenovo Flex 2 or Flex 3, you may have a situation in which the unit goes to sleep but will not power back up.  Instead the power LED just keeps flashing at you.

Many people believe this is related to Windows 10 but I have read several first hand accounts from people who had the problem with Windows 8.1, so I am unconvinced.  Regardless, it would appear the problem is related to power management settings.

In my case the solution was to pull the battery, wait 2 minutes and then reconnect the battery.  The problem is that in a Lenovo Flex 3, that is not a simple as it sounds because the battery is internal.  Fortunately, it is still not very hard to do:

  1. Unplug the unit from the AC power and all other devices (i.e. USB mouse…)
  2. Turn the unit over and remove all 10 screws
  3. From the corner under the screen near the network and Kensington lock port, use your fingers to pry the back off
    1. I have done this 4 times now, without any damage to my unit
  4. Disconnect the battery connector cable from the motherboard
    1. In my case my fingernails just would not do it, so I used a tiny ‘flat’ screwdriver to pry each end of the black plastic connector out of the metal header
  5. Let it sit for a few minutes (2?) so that everything on the motherboard drains.
  6. Slide the battery connector back into the header
  7. Press the power button and see what happens
    1. If it powers up, put the back on and screw it down, your done
    2. If it does not power up, disconnect the main battery again, pull the BIOS battery, let it sit for 5 minutes (to drain) then plug the unit into the AC power adaptor (i.e. do NOT reconnect either battery) and power up
      1. If this works, power down the unit, reconnect both batteries, put the back on and screw it down, your done
      2. If your Flex 3 still does not work, you likely need to put everything back the way it was, call Lenovo for warranty support and make sure you don’t tell them you pulled it appart because they might void your warranty (or buy a battery off eBay)

View Comments

  • Flex 3 1480 with amber blink battery issue with no charge or on-battery operation.

    Solved: Opened label on battery and charged each cell to 4 volts using 500 ma charge rate, so battery OK.
    In Device Manager, uninstalled the Microsoft ACPI Compliant Battery Controller. Shut down normally.
    Unplugged AC, disconnected Battery, and removed coin style battery from MoBo. Waited 1 hr and reconnected batteries.
    Powered up with AC (took longer than usual). Amber blinking LED now constant white. Battery monitor on task bar now shows 90% and now charging. Now working on battery as well. Able to update BIOS too.

    Multiple attempts failed until I pulled the coin battery!

    • Hi Gary;

      That is a great idea. Disconnecting the "coin" battery will drain the laptop completely and the BIOS will loose its settings, which could be causing issues. The defaults for the BIOS are likely fine and if they are not, they are easy enough to change. I would be surprised if the ACPI Battery Controller were the issue, but it costs nothing to remove it as it will Plug and Play on reboot so that is also a good idea.

      Thanks for the suggestions.

  • Ian,
    You are a tech saver. I thought my 5 yr old Flex was toast. Found your advice after alot of searching and just went thru it and voila it worked, miracle. I can't thank you enough. I thought i'd have to spend $1,000 to even come close to my nice 17.3" of old. Not to mention recent unbacked up data potentially lost, yikes
    I see you mentioned no longer having Lenovo, I always liked Lenovo, what might you recommend ? I really like the flex/yoga, pretty attached, not an HP fan but?? Hard to find 17.3" screen anymore, want i7, SSD, guess i may have to go 15.6". Everything's really sold out during this horrible pandemic.
    Thanks a million.
    -Christine

    • Hi Christine;

      Thanks for the kind words, I try :)

      As for a replacement, I have stopped sourcing Flex/Yoga/2in1's from Lenovo because I have found too many problems with the hinges. Among other issues, I have found that the hinges seem to be too stiff for the chassis, or more correctly, the chassis is too weak for the hinges so some of the chassis either crack or have excessive flex with puts big stress on the motherboard. I have not sourced a new Lenovo in a couple of years so it is very possible that they have improved their chassis but today I source mostly Dell products. I really like the https://www.dell.com/en-ca/shop/2-in-1-laptops/sr/2-in-1-laptop/intel-core-i5?appliedRefinements=5744 and if you call them (rather than just ordering online) you can almost always get a discount just for asking. I have even sourced a few from Costco in recent years for some of my smaller customers.

      I hope that helps... Stay safe :)

  • Went through steps 1-7, screen still not working.
    If the Flex 3 won't work on AC only, would it really be worth replacing the battery?

  • I've had this issue repeatedly where I've powered down the computer using os shutdown only to come back hours later with the fans running loudly and at full tilt. Touchpad is off or disabled. Keyboard only types 6 and WiFi is off or disabled. Luckily the touchscreen keyboard enables boot to OS to backup docs and pictures and email. Repair requires complete OS replacement from USB backup. I've found no other solution except to reinstall the OS and sometimes that step requires repetitive attempts. What is the problem with these computers?

  • @Peter (the retired IBM tech):

    This happened to a Lenovo T470 while I was flashing the BIOS as I have done literally over 100 times with other Lenovo laptops. Pretty simple process.

    I had a dock attached to it while I installed the BIOS from the Windows 10 application, and when it should have rebooted to actually flash the controller, it went to standby. The power button LED was breathing. It was completely unresponsive, and the only thing that would wake it was to remove the external battery, and detach the internal battery.

    It rebooted and the Lenovo boot splash screen has been showing with "Flashing Embedded Controller... Please do not power off!". That screen usually goes away in a matter of seconds, but it has been that way now for over 15 minutes. I am afraid to power it off.

    Would you suggest anything?

    Thanks in advance.

    • Some motherboards have two BIOS' for just such a situation. Specifically GigaByte boards have a backup BIOS. I don't think Lenovo does, but I would check into it. Otherwise, I would check for a jumper (likely two pins you have to short with a screwdriver) to reset the BIOS to factory settings. Both are longshots but worth trying before scrapping the hardware. :(

  • I followed your instructions and removed the BIOS battery and it solved my lenovo! THANKS! Took me several weeks to fix it!

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