Hi,
I identified the cause of my Asus ux305 laptop not charging the battery, it's a shorted mosfet on the charging circuit.


The ref printed on it is

A5 VNB
6S0501

I searched online with this ref but impossible to find.So I used AI :
- Chatgpt told me the only important part is A5 VNB and it's a N Mosfet that can be replaced by AON6414A
- Grok told me it's a P mosfet not an N, and can be replaced by P0903BEA
- Gemini, to which I sent the pic, asked me to do some measurements with a multimeter in diode mode, and conluded it was a P one. And since it has no visible little paws, it a not a classic SOP-8 but a DFN 5x6, so the replacement ref is AON6411

So I am not sure which one to believe....
Thanks for any help

 

It's that mosfet

 

It's that mosfet

View attachment 364046

Thanks, that's what Grok suggested it's a N model, but Gemini tells me it's a P model and won't fit:


1. Wrong Shape (Package)

• P0903BEA is a SOP-8 package. It has long "gull-wing" legs.
• Your Asus MOSFET is a DFN 5x6 package. It is flat, has no long legs, and features a large thermal pad underneath.
• Result: You cannot physically solder a P0903BEA onto your board because the legs won't match the pads and it lacks the bottom cooling plate.

2. Branding & Marking

• The "A5" code on your photo is the specific factory shorthand for Alpha & Omega's AON6411.
• Potens (who makes the P0903 series) uses different codes. Buying a P0903BEA would be like buying a Ford part for a Toyota; even if it does the same job, it won't fit the bolt holes.

3. Polarity Risk

• The P0903 series has many versions. Some are N-Channel and some are P-Channel.
• Your measurements confirmed you need a P-Channel. By ordering the AON6411, you are guaranteed to get the correct P-Channel polarity in the correct flat package.

Your Final Plan:

1. AON6411: The "True" replacement. Fits the "A5" mark and the flat shape.
2. AO4407A: Your backup. Only use this if, after desoldering, you realize the board has 8 distinct long-pad tracks (unlikely given your photo).

 

It's that mosfet

View attachment 364046

In fact it seems you're right, thank you very much !

 

I searched online with this ref but impossible to find.So I used AI :
- Chatgpt told me the only important part is A5 VNB and it's a N Mosfet that can be replaced by AON6414A
- Grok told me it's a P mosfet not an N, and can be replaced by P0903BEA
- Gemini, to which I sent the pic, asked me to do some measurements with a multimeter in diode mode, and conluded it was a P one. And since it has no visible little paws, it a not a classic SOP-8 but a DFN 5x6, so the replacement ref is AON6411

At this point, AI isn't very intelligent when it comes to electronics.

A member recently fed an AI a picture of a COB LED strip that was labeled 3V and asked what the voltage was. AI said it was 5V... The member posted asking what he should believe. I told him to trust his eyes more than an AI.