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.Lenovo-Flex-3-2-remove-back-to-access-battery-hard-drive

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. Lenovo-Flex-3-2-disconnect-batteryDisconnect 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)


  1. Avatar
    Gary September 20, 2020 at 5:05 pm

    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!

    • Ian Matthews
      Ian Matthews October 1, 2020 at 11:54 am

      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.

  2. Avatar
    Christine S September 5, 2020 at 7:34 am

    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.

    • Ian Matthews
      Ian Matthews September 18, 2020 at 9:16 am

      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 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 🙂

  3. Avatar
    Linda May 11, 2020 at 11:59 am

    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?

    • Ian Matthews
      Ian Matthews May 13, 2020 at 8:38 pm

      That is difficult to say but I probably would not. 🙁

  4. Avatar
    bainian December 27, 2019 at 12:47 pm

    Solution works great for my Flex 3. You saved my day. Thanks!

  5. Avatar
    allberk December 27, 2019 at 11:01 am

    Thanks this procedure was so helpful

Questions or Comments?