Melted motherboard component... Can my laptop be saved?

Hi everyone,

I've been having problems with the modular battery for my asus w3v laptop, which I think created a short-circuit, which in turn melted one of the motherboard components:



The laptop won't turn on anymore, and the AC power adapter light (on the power cord brick), blinks off whenever I connect it to the laptop (which indicates that there's probably a short somewhere).

What really sucks is that I just bought a new HDD, battery and ram for this laptop, and don't have the money to spend on a whole new computer. Does anyone think that it is salvageable? I'd probably have to get a new MB...

One more thing, when I took the laptop apart, one of the white plastic connectors (for the power button) was really brittle and broke apart when I tried to disconnect it from the motherboard. I can still push the wires in, but I don't know which one goes where!!

Does anyone have any idea of the order in which order the three wires fit into the connector? There are 4 possible spaces... You can see the three wires dangling in the picture below. They fit into the white connector on the immediate left (with the blue/red pen marks).



Any help/advice would be greatly appreciated!

 

One more question: would it be possible to use a motherboard for an updated model like the w3j instead?

 

I am not sure what that chip does exactly. One can only asume you need a new mobo. asus estore still sells them. you will also need the cable which comes with the w3 lid i think. The red and green are important. the black should be ground. It cant hurt too bad if you just tried it out. The button should work if you figure out the correct configuration.

 

w3j is a diff motherboard and bottom panel. you can use w3k lid and power button and cable

 

Thanks for the reply! I looked at the asus e-store, and unfortunately the w3v motherboard is out of stock. I doubt that they will make any more of them, but I'll call tomorrow and see.

Also, you mentioned the w3k lid and power button but I can't find this model on their website. Did you mean something else?

 

sorry i meant w3j, also w3a and z63a have very similar design. the only thing that differs is the bottom panel and chipset all else is the same.

 

I called asus, but unfortunately they no longer carry any w3v motherboards... I've also looked around online, but I've had no luck either.

It's looking like I will have to get a new laptop . At least I managed to return the hard drive and battery that I bought not too long ago. I'm still hoping that I'll be able to fix this laptop though because it would be a shame to just throw it away!

 

because of its proximity to the cmos battery, i would say those 2 DRAM chips store the volatile BIOS settings.
the 4800b that melted should be swappable for the 4835b (whichever you manage to find), but i have no idea where you would get them.

 

Well you dont want to throw it away. WHy put it in a landfill? you can sell the lcd lid and bezel on ebay. you can even sell the top and bottom cover on ebay. you can sell the hdd and cpu.

 

If you guys know the model number of the chips, you can use this website to find a shop that carries it and has it in stock. Doing a quick search on 4800b lead me to several "MOSFET N-CH 30V 6.5A 8-SOIC" parts at Digi-key. They are like a $1.51 each and shouldn't be too hard to replace if you have the tools and experience. If you are near the SF bay area I may be able to help.

Although, the bigger question would be WHY did it fry and will it do it again with the new parts. Also what other parts might have gone with it. For a buck fifty plus shipping it might be worth trying.

Edit: I re-read the information above and am pretty sure the digi-key part is correct. This mosfet most likely deals with the power / charging for the laptop and probably blew due to the battery issue. I do not see a CMOS battery in the pictures above and all listings for "4800b" or "4835b" point to mosfets. The big square part in the pictures is an inductor (seems to be a 100 uH at that) and is most likely part of the charging / power circuitry as are the mosfets.

If you try this repair be careful to get the correct part. The 4800b is a N-channel mosfet where the 4835b is a P-channel mosfet, therefore they ARE NOT interchangeable.

Hope this helps.

 

Thanks for all of the info, it really helps. I do have some experience soldering, but haven't done so in a while. I'll order a part on the findchips website you suggested mr_milo (thanks for the link) and see what happens! You are right, for $1.50 I can't go wrong.

The main thing I am worried about for the repair is the heat from the iron frying the new component (or other components on the board). Any advice on how to minimize this risk?

One last thing: Is it possible that mixing the correct order of those wires (the red/brown/black ones in the last picture) could cause some major damage? I'd hate to repair the MB only to mess it up again due to the powerbutton wire configuration...

Thanks again for the help, I really appreciate it. And don't worry Geared2play, I wouldn't actually throw the laptop in the garbage can

 

I'm not sure about the three wires since I do not have this model. I can't think why there are three wires unless one of them is for a light. If this is the fact then yes hooking them up wrong has the chances of causing some more damage.

I sent you a PM about the IC , some solder tips and a bit of caution about the job.

Hope this helps.