battery - No charge, Blinking power LED on Lenovo Y50 laptop

My laptop no longer charges while turned on.

Lenovo Y50-Y70 UHD 59425943

While computer is off:

• Plugged in (before reset trick): No LEDs or charge.


• Plugged in (after reset trick): Computer charges fine, LED showing charging

While Computer is ON:

• Plugged in (immediate): No charge, No LEDS


• Plugged in (after about 3 mins): No Charging, LEDs all blinking in sync.

Things I've tried that didn't work:

• New battery


• Reseating the RAM


• New A/C Adapter


• Uninstalling the AC Adapter and Battery drivers in Windows, and reinstalling Lenovo's Power Management program.

Things I tried that helped:

• I tried removing the battery and AC adapter and pressing the power button 10x at 1 second intervals then holding the power button for 30 seconds. (this resets the power in the capacitors and resets something in the BIOS I have heard). It used to never charge, even while turned off. Now it charges while turned off, but not while turned on.

Wondering what part of the computer must be broken? I know this has an advanced power management features, including a battery with it's own firmware, but everything seems to be set up correctly on those settings.

Answer

This board does not have a DC-DC power converter board. Power boards on laptops vary, but in this case, there is a DC jack that goes into a mini 5pin molex then straight into the motherboard.

When I took out the connector using a disassembly video on YouTube as a guide, it was very obvious what the problem was. A power surge had caused the plastic molex to melt completely. You can see the burn marks here. All these holes should be white, two are burned black.

Lenovo quoted me $350 to fix it, including everything. This part (DC Power Jack & Harness) is $5 on ebay, and about 2 hours of work to replace for a new guy. About 45 minutes for a pro. Just screws, no soldering. However, in these cases sometimes the capacitors can be damaged. Those are under a dollar each, but requires melting the solder on the reverse side of the board, and then re-soldering it.

The lesson here is ALWAYS USE A SURGE PROTECTOR (2,000 joules for computers)