Re: Asus N76VB identifying 'A5 GNA'
That's an N-channel symbol it seems to me. I do not understand why it is depletion though....
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Re: Asus N76VB identifying 'A5 GNA'
I do not understand why you guys think the A5 GNA is a P-channel MOSFET. I have not seen any evidence in this thread. On the contrary the BQ charger IC datasheet specifically mentions it drives N-channel type ACFET and RBFET.
I have therefore replaced the 2nd jack (RBFET) with a Microchip MCP87130T-U/LC MOSFET, N-CH, 25V, 54A, 8PDFN.
Laptop works again.
My problem is solved, some of my questions in this thread remain valid.
Regards, Leon...Last edited by likewise; 05-04-2016, 12:36 PM.
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Re: Asus N76VB identifying 'A5 GNA'
I already posted this datasheet in post #8?
This does not answer my question though... How can I tell it is this part?
Thanks.
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Re: Asus N76VB identifying 'A5 GNA'
Thanks. I have two remaining questions:
1) Where can I find that A5 means P0903BEA?
2) In posting #7 you mentioned "p- mosfet", this confused me.
So we agree this is an N-channel MOSFET?
Thanks all! Great help here....
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Re: Asus N76VB identifying 'A5 GNA'
But what part number is on the board?
If it's a P0903BEA MOSFET, why do you think it is a P-channel MOSFET?
If it's a different MOSFET, do you know what kind it is?
How did you measure the P vs N MOSFET characteristic?
I am not a laptop expert, but I do have some EE background....
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Re: Asus N76VB identifying 'A5 GNA'
In your screenshot there is "N-MOSFET" in front of "P0903BEA".
Also, the datasheet of P0903BEA mentions "N-channel MOSFET".
Could it be the confusion is from the "P" in the part name (P0903BEA)?...
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Re: Asus N76VB identifying 'A5 GNA'
I am confused. P0903BEA shows as an N-channel enhancement MOSFET from this datasheet:...
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Re: Asus N76VB identifying 'A5 GNA'
How can we find out without desoldering?
How would the (schematic) design differ from the bq24725a reference design, where the datasheets specifically mentions it drives N-channel FETs ACFET and RBFET?
Can someone explain why there are two identical MOSFETs placed with a common source, in opposite directions? I'm trying to understand how this design works.
Thanks, would like to clear up what is the correct part....
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Asus N76VB identifying 'A5 GNA'
Hello all,
On my Asus N76NV I am suspecting a bad MOSFET (near-zero drain-source resistance) but cannot identify the part 100%.
The part is marked:
A5 GNA (sure)
GP0108 (not sure)
See photo in attachment.
This is the RBFET that matches the TI BQ24725A reference design.
Motherboard rev. 2.0.
Laptop only ran on remaining battery charge, did not charge, did not power-up without battery. It did power-up when I put 19V on the drain of this MOSFET.
ACOK=2.87V
ACDET=2.57V
I would...
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Re: New Members - please post your introductions here
Trying to fix an ASUS N76VB laptop I came across this forum. By just reading about others solving their problems I could quickly learn and find what the problem with my laptop is.
I have an EE background but mostly I am programming electronics, i.e. writing embedded software. It's nice to be able to read schematics though
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