Does anyone know what this electronic chip is?

Question

When I opened the laptop that apparently having power trouble, I decided to check the ICs that are responsible to give power throughout the board. I counted 6 of these, and I think a couple are shot. I want to attempt to repair it as I have the necessary tools as well as an automatic desoldering machine that will automatically heat up and remove the soldered area for replacement.

The IC (or Power MOSFET I believe) in question is: A1 KND 900201, but I just couldn't find it online for some reason. As for the laptop in question,  it's the ASUS UX31L. For additional details, I have asked the same answer here 4 months ago, but I got no proper/direct answer:

https://answers.yahoo.com/question/index?qid=20200220062251AAFPacx

Taking it to a technician is also out of the question. People here are literally like "Yea, the motherboard is burnt, and nothing can be done. Buy a new laptop". Heck no! I'm not lazy! I'll attempt to repair it at least, but if only I could know the name of that Power MOSFET to order a new one. (At least I'm guessing it's most likely a Power MOSFET).

Robert J · Accepted Answer

This is a schematic for a version of the Asus UX31:
https://www.rom.by/files/1bc0e_asus_ux31a2.pdf

Have a look around Page 60; that's the main power control with the power FETs etc. and see if it uses similar parts.

There are many equivalents for most.

Post pictures of the components and connections if you need more info, or ask on the Electro-tech forum - that's dedicated electronics to more appropriate.
electro-tech-online.com

(Again, post detailed pictures).

Starrysky · Answer

1--searching for a part like that might not be possible if laptop was made some time ago in Taiwan.  Part might not ever have been marketed in other countries.  Might be proprietary.  Search Allied or Digital-Key on line catalogs.
2--even if you replace that part, might it not burn out again?  You don't know the cause of the first failure?
3--Why not just replace the faulty motherboard with a working one?  Search Google.  I found a good board for my Lenovo G555 after the video chip detached from heat cycling in 3 years of normal use and repairing it in oven failed 2nd time.  Board was simple to replace, not that expensive.
4--Google search shows verious models of the UX31 board from Ebay, Newegg, Walmart, others for less than $130.  Even a cheap faulty board might have a good part you could salvage.

Dick · Answer

Have you even tried to find someplace to buy that "power MOSFET"???  I doubt you'll find one and doubt you'll find a price that is reasonable.

Does anyone know what this electronic chip is?

3 Answers