Help locating a replacement chip

[milkster]

Hi all, i'm new here and i'm hoping some of you might be able to help me. I realize that this forum is mostly about CAPS but i thought my problem is closely related and it thought I give it a shot....

Here is my delema, the other day a chip on my motherboard burn out while i was plugging the power cord back into the powerbar. I have some minor soldering skills which makes me think I can pull this off.

I have located the burnt chip but now I'm trying to find a place where I can buy a replacement. This chip is found on my Asus P4P800S-X mobo. The chip has the following markings APM2054N. I have determined that the original chip is made by Anpec in Taiwan.

Does anyone know who might have an equivalent replacement?

I'm providing some pics of the burnt chip and good chips found on the mobo in a different location.

Picture of the burnt chip

Picture of good chips found in different location on mobo

Datasheet that I found for this chip

Any help would be appreciated.

Thanks

[Toasty]

Re: Help locating a replacement chip

See this thread:

https://www.badcaps.net/forum/showpo...22&postcount=2

[milkster]

Re: Help locating a replacement chip

Thanks Toasty!

I followed the links in the other thread that you pointed me to and it looks like i found some comparable replacements but i'm not 100% sure if they are.

Can someone confirm if the following is a comparable replacement part?

From Mouser:
Mouser Part

From Digikey:
Digikey Part

My only concern is that the shape of the chip is different. The above chips are SOT-223 where the original seems to be a TO-252. I don't know what those numbers mean but maybe one of you can let me know.
Also some of the spec numbers are higher than the original specs - is this bad?

For example:
Vdss is 30V - Original is 20V
Id is 6.5A - Original is 6A



Thanks

[NxB]

Re: Help locating a replacement chip

Specs seem OK. I think the package is different so it won't fit. Did you test the other mosfets on the board? Any of them shorted or dead? If you have scrap boards you can probably steal some good mosfets from a similar class board. Which part of the board are they on?

see

http://www.mobileelectronics.com.au/...hp/t70056.html

http://i10.photobucket.com/albums/a1...884/MOSFET.jpg

[milkster]

Re: Help locating a replacement chip

Specs seem OK. I think the package is different so it won't fit. Did you test the other mosfets on the board? Any of them shorted or dead? If you have scrap boards you can probably steal some good mosfets from a similar class board. Which part of the board are they on?

see

http://www.mobileelectronics.com.au/...hp/t70056.html

http://i10.photobucket.com/albums/a1...884/MOSFET.jpg

Thanks for the info. Are you saying that the SOT-233 pins will not align properly to the board because of the shape? If so, how would I locate a TO-252 - I can't seem to find it on the mouser or digikey websites - i just don't know what i'm looking for...

I didn't test the chips yet and I don't have any other spare boards that i can steal from. I'm debating if its worth trying to fix this or just buy the same board from ebay....

This mosfet is near the corner of the board - when looking at the pic i provided the main power header is right above the burnt chip, to the top right is the memory and to the right of the memory is the CPU socket.

[Wizard]

Re: Help locating a replacement chip

These burn-up is sign something is seriously wrong. Shorted load, bad controller that controls these transistors etc. And I ask, it only fried when power is plugged back in at the mains?

Also this can mean bad power supply ruined the board as well so consider that as possiblity.

Cheers, Wizard

[milkster]

Re: Help locating a replacement chip

These burn-up is sign something is seriously wrong. Shorted load, bad controller that controls these transistors etc. And I ask, it only fried when power is plugged back in at the mains?

Also this can mean bad power supply ruined the board as well so consider that as possiblity.

Cheers, Wizard

It burnt when i went to plug in the power cord into a powerbar. I saw sparks inside the powerbar socket as soon as i put the cord in.....then tried to turn on and no post.

I get power to the board, fans spin, lights on board are on, but no video, no beeps. I figured I can try to replace the burnt chip if I can get it cheap and if it doesn't work then I'll have to forget about it. But it seems like trying to locate a replacement chip is not as easy as i thought.

[NxB]

Re: Help locating a replacement chip

If you look at the picture, you will see that it doesn't align and is probably a different size. You have some components in your pic that are that package, notice how they are different.

http://parts.digikey.com/1/parts/101...stn4nf03l.html

Looked up your mosfet on google and found a cross reference chart from another company. That should be a good replacement. I'd have a look into your power supply if it did that when plugging it in. Definitely don't replace it and plug in the same power supply without testing. If you're lucky you only blew out the one mosfet and maybe some of the ones in the same circuit. If your unlucky you took out your chipset/cpu or power chip.

FYI-

I take these off with a hot air gun not a soldering iron. There is solder under the drain, that's why the middle leg is cut. Doing these with a soldering iron is annoying but not impossible.

Never plug a hot supply into the atx connector as it can do things like this. Was the 4 pin 12 volt cpu power plugged in too?

I'd test the other mosfets and obvious stuff on the board and replace them. Maybe it burnt quickly enough to not fry anything else. How much is a new board vs spending $10 on mosfets to try it?

[NxB]

Re: Help locating a replacement chip

I get power to the board, fans spin, lights on board are on, but no video, no beeps. I figured I can try to replace the burnt chip if I can get it cheap and if it doesn't work then I'll have to forget about it. But it seems like trying to locate a replacement chip is not as easy as i thought.

This is better than a completely dead board but not by much. Does your chipset get really freaking scalding hot? Does the CPU heat up at all? Also check the mosfets in the VRM near the CPU.

[milkster]

Re: Help locating a replacement chip

Looked up your mosfet on google and found a cross reference chart from another company.

Can you provide a link for this? I'm looking for a supplier/distributor in North America

Never plug a hot supply into the atx connector as it can do things like this. Was the 4 pin 12 volt cpu power plugged in too?

I'd test the other mosfets and obvious stuff on the board and replace them. Maybe it burnt quickly enough to not fry anything else. How much is a new board vs spending $10 on mosfets to try it?

I didn't plug in the ATX Power connector to the mobo when this happened...I was simply moving the PC to a different location (the whole case with everything closed) and when I plugged in the external power cord into the powerbar that is when the sparks flew inside the powerbar socket.

A new board on ebay right now is around $70 with a CPU.......

[NxB]

Re: Help locating a replacement chip



Cross ref.

If you look on digikey for the one I showed you (STN4NF03L), you can order less than 4000 of them. Just type in the part number. It was simply the first link I found.

[Toasty]

Re: Help locating a replacement chip

I disagree with the replacement specs. You say Id was 6A? Try 20A...

https://www.badcaps.net/forum/attach...achmentid=8442

I'll do some checking, but the closest I've found so far is a 33 watt piece, not the 50 watt like the original. Even Anpec (the manuf. of the orig) has dropped the 2054 number.

More later.
Toast

[NxB]

Re: Help locating a replacement chip

20A is a lot of current. If your PSU is dumping 20 amps through the mosfet its probably screwed up. STN4NF03L is a direct replacement according to the cross ref sheet, its 6.5 amps. Plus what about the other mosfets on the board? The power supply most likely caused the failure anyway and needs to be checked out. Doubt asus made a 15 amp mistake. Who made the power supply?

If the chipset is gone, its all moot anyways without a reballed replacement chip.