Lenovo Flex 3 (1580) repeatedly says "plugged in", followed by "unplugged" over and over (Not charging)

[001lost001]

Hi, the problem is around the charging circuit, a component (transistor, chip) is defective on the motherboard.

The problem could be just a transistor, it's easy to find and repair.

I too have been through all of the easy stuff, and would like to pursue replacing the faulty transistor. Any information you can provide would be greatly appreciated.

 

[001lost001]

The battery is marked: 11.1v 45Wh 4050mAh

So my question is, would something like the device below function as an independent charging circuit?

3Series 11.1V 12V 12.6V Li-ion Lithium 18650 Battery Charging Protection Board PCB BMS Module(10-13A)

AVAILABLE HERE

I am thinking remove the charging port cable from the MB and solder the ends directly to this board. Then connect the output of this board directly to the battery. I can't locate the image right now, but if you lift the black plastic wrapping from the corner where the wires enter the battery pack you will find 7 test points one could easily solder connections to.

Using this method you will lose the ability to see the charging status because it will always think it's running off the battery. Personally I feel that would be a small price to pay for a functional machine.

~lost

 

[jarotech]

What is the problem with the laptop? Does it work with the adapter and not with the battery?

 

[yort]

Hi, the problem is around the charging circuit, a component (transistor, chip) is defective on the motherboard.

The problem could be just a transistor, it's easy to find and repair.

What is the problem with the laptop? Does it work with the adapter and not with the battery?

Jarotech, could you help me identify what transistor or component is causing the problem with the charge circuit. I am having the same problem with my lenovo flex 3 1480. Lenovo wants $880 for a replacement board and I haven't been able to find a used one that matches my computers component specs.

 

[jarotech]

Jarotech, could you help me identify what transistor or component is causing the problem with the charge circuit. I am having the same problem with my lenovo flex 3 1480. Lenovo wants $880 for a replacement board and I haven't been able to find a used one that matches my computers component specs.

Sorry, I have not found a schematic for the Lenovo Flex 1480, so without the schematic, it will take too much time to find the defective part.

 

[Joey_nINJJa]

Three questions: Where can I get a replacement for the transistor that is most likely faulty, can a hobby-grade soldering iron be used to replace it, and where would I find it on the board?

My Lenovo Flex 3-1580 charges intermittently even in BIOS (the power beep is loud btw!) and did not charge at all when left charging for 24+ hours. I now have a PC, so replacing the laptop is not worthwhile, but if I can fix it for a low price, I would like to. Definitely not still under warranty. I believe the warranty expired nearly two years ago, if it even had warranty.

 

[duckens]

Had one of thease come in the shop... long story short is that a resistor that feeds the vcc pin of the bq24780 was high. it should have 20v to the pin but was getting 3. replacing it seams to have fixed it. it should be a 10 ohm resistor. https/vinafix.com/threads/lenovo-yoga-500-not-charging.31664/ last post has picture