Asus N61JQ mosfet

Hi, I am looking for help. My asus died after long years. I found out why. It was one of the mosfets. I want to replace it, but i can not get its number because it is fried. https://postimg.org/image/4cfvqe14t/ . This is link of pic which shows burned part. Please help.

 

Tried image-googling 'Asus N61JQ motherboard', but no luck. I'd wing it by using the marking on the other 8-pin chip right next to it, chances are it serves the same purpose. Too bad the board isn't labelled; at least with F***, R***, PQ*** you'd be sure of what it did, even if not the values.

Can also try and find the schematics by looking at the pcb manufacturer's part number. That's a bit of a long shot though, since unlabelled boards aren't meant to be repaired, only replaced wholesale (if even that).

 

Man I recycled my old N61JQ a few months ago. I would have just sent it to you for the shipping cost if I still had it.

 

Is not the same board comes for few models? I know that for this particular model it is n61ja rev 2.0 As far as i know it is the one board which goes with my asus. Thanks

 

I have tried to look up schematics. But is no use of it. Or maybe i don't know where to look for it.

 

I am yet to dissassemble but I think I have the same issues

I am thinking this may be of use
http://www.badcaps.net/forum/showpost.php?p=516486&postcount=22

Let us know how you go

 

Well I just need marking of that mosfet drive. In order to replace it. Because there is so many of them. That file it gives only layout nothing else. If You can check that pic in previous posts. And write down that marking a would try to get that part and see if i have any luck. Thanks

 

I found some parts number in that file, but is not what i do need. it doesn't help me at all. I have pins, nails net and part file.

 

well i keep trying to get most of it. and i got only to J8803 0.3891 -3.5513 270.0 D1 (B) 'NB_PWR_FB_SHORT_PT', 'NB_PWR_FB_SHORT_PT' last to repeating is device and outline,
can't get anything else from that

 

this smd chip is heating up everytime then it is on. so it is a prbolem that picture is showing that this chip meltdown some of plastic from cover start digging for mark i know some of numbers are 4 and maybe 53 or so

 

RJK0353DPA seem to be the most likely candidate, which would be the same chip as the unaffected one close by, except rotated 180°. Package doesn't match the photo though, but the pdf is just a general design to the actual pcb manufacturer and the modern type is compatible with the old footprint anyway. Couldn't find the Renesas part on mouser, but the Vishay SIR166DP-T1-GE3 would do fine.

They're part of the 1.5V circuit driving the CPU, so ... figures it won't start then. Also; oc'ing? The Vishay would be a better choice then as well, having a little higher drain current and power dissipation.

Just to be sure; mind the orientation. Pin #1 (with the dimple), goes bottom-right.

 

Here are views of the N61JQ motherboard in the Badcaps thread
http://www.badcaps.net/forum/attachment.php?attachmentid=101903&d=1419799148
http://www.badcaps.net/forum/attachment.php?attachmentid=102135&d=1420207221

Maybe enlarge and use magnifying glass may give clues ;-)

 

Thanks for help. About that vishay it is n channel and the one which is next to bad one is 4435bz. Which is p channel. I do not know exactly what is difference between them.
Thanks for pics. These pics is low resolution can not read anything from them.

 

The major difference is in direction the current is flowing; drain to source voltage is negative (P-type) or positive (N-type). A multimeter might help here, provided there'll be (a little) voltage right up to the mosfet. Measure between any of the three bottom-right pins (source) and any of the four left pins (drain).

The 4435BZ is quite different from the Vishay model, having only 1/4th the current rating. Even if it turns out the circuit needs a P-type, it'd be better to use a higher capacity type. Since we don't know its intended load, a little overkill would be desirable.

 

hi
it is PKYBU FDS 4435BZ if i read correctly
unmount it
check for a short before soldering a new one first
may be you have a bad cap somewhere or melt pcb which would need a bridging of melted zone
if it is a bad cap, it is on the 19V line (a fat cap i would say), this can be anywhere on the board, not only near this mosfet
personnally i use multimeter and thermal cam to find them fast
if there is no short, solder a new one
btw, any other laptop's power 19v mosfet will be fine if it uses same 4.74A as power source
just check for pin 1 position