Asus k52f short

[Stevie2001]

Re: Asus k52f short

Just uploading a picture of openboardview in use ,so you can see the difference between it and boardviewer.

so the image you posted,it don't show any connections to the intel chip.
but when i use boardview it shows connections to 1 pin of the intel chip

here is the focused transistor am intersted to find short.


the connected parts means how many components is connected to this line.

look up this part on your boardviewer and se and compare it and look close their is 1 pin on intel chip connected to that transistor.

i hear on video from a tech that half short means part of a section is shorted.
full short is all over.

i think this board has had beating.

[SMDFlea]

Re: Asus k52f short

QUOTE: "so the image you posted,it don't show any connections to the intel chip.
but when i use boardview it shows connections to 1 pin of the intel chip"

I know that,as i said it was only to show the difference between boardviewer and openboardview. So...... i`ll post some more pictures of D2701 pins 1,2,3 , using OpenBoardView.

Test resistance to ground on each pin, and post your results here .

[Stevie2001]

Re: Asus k52f short

Ok thanks do i check on ohms mode

[SMDFlea]

Re: Asus k52f short

diode mode beeeeeeeeeeeeeeeeeeeeeeeep

[Stevie2001]

Re: Asus k52f short

diode mode beeeeeeeeeeeeeeeeeeeeeeeep

My multimeter diode is seperate option and beep.
Should i select the beep and give the values

[SMDFlea]

Re: Asus k52f short

yes

[Stevie2001]

Re: Asus k52f short



RES 10K OHM 1/16W (0402) 5% TA-I/RM04JTN103
most of them are 10k ohm and 200ohm
they are either no buzz or no reading from them or buzz with probe to gnd both sides.

look at the one on the right its missing.
i noticed few missing in most areas and i ignored them as i thought its normal according to shem or boardview.

i did a quick test of few of them their are no beeps
i will update you with reading and non reading or with gnd

i will try and make accurate reading with picture so its easy for u

[Stevie2001]

Re: Asus k52f short

am 100% certain its u2001 ic.
their are other pin that connected to hdmi port are shorted and i kind of traced and seen that they also have 1 pin connected to that u2001 ic.

this board is a toy so is it ok for me to run a reflow test on it lol using heat gun.
its my first time so dont mind trying it out but can you tell me what way i should do it,should i add flux.

[Stevie2001]

Re: Asus k52f short

Update.
Used hotair and removed the intel chipset ic
Used solder wick to clean the pads and the transistor short is gone.
what do you make of it

[gordo999]

Update.
Used hotair and removed the intel chipset ic
Used solder wick to clean the pads and the transistor short is gone.
what do you make of it

Yes...but did that fix the problem with the blown power board?

I have the same problem, pretty well exactly. Blown, JMC251, the K1 LED driver and the lid switch IC, which is a Hall Effect chip.

I am approaching this differently, it's an odd one. The symptoms point to an over-voltage condition and quite an over-voltage considering the degree to which the JMC251 was toasted.

I have loads of experience in electronics and I don't feel good working blind. Therefore I am tracing the pertinent circuits to see what I'm dealing with. As someone indicated earlier in the thread, it's likely a feedback condition from the mobo. What caused it is the question.

You checked for DC on the power supply, the 19V, but did you check with a scope to see if there was any AC riding on the DC? I doubt it, but when checking a DC power supply it helps to look for extraneous signals on the DC, especially AC.

AC will fry a chip. Mind you, if you're getting a full 19V from the supply it's unlikely a diode has blown in supply, or is leaking.

Your approach was correct IMHO, to use a current limited DC supply. I am currently building one.

I was given the laptop with an Asus K52jr mobo. It did not work and beer and been spilled on it. I cleaned up what was visible and checked for shorts. When I first powered the device up, the power LED lit up but nothing else was going, even the fan. That indicated a power supply issue to me since a dead s/c on the mobo P/S would not have allowed the power LED to light.

I traced the 5V and 3V power supplies from where the 19V enters that section. Everything looked good up to there. The +5V and +3V are DC-DC converters using FDMC8884's, Mosfets. Both are driven from the RT8206 on other side of mobo and drop the 19V down to 5V and 3V.

The 5V/3V start out as 5VSUS and 3VSUS after conversion from 19V and the first twp FDMC8884s accomplish that. The next two convert the SUS voltages to regular 5 volts.

The SUS is related to the sleep stages, as in SUSpend. They come first because it is desired to shut down the regular 5V/3V for sleep and hibernate. If problems are encountered and the SUS voltages are there, there is a slew of other circuitry to control the various voltages.

The 3V Mosfets were open, hence no 3V. I may have done something while tracing, when I plugged it back in to test the +5V/+3V, the chips listed above began to cook. A check of the 19V input to the 5V/3V section indicated a short to ground.

Static could be an issue since a static charge from fingers or clothing can turn a Mosfet on. If one or more are turned on when the power is applied, there is no saying what could happen.

It's really odd that just the 3 chips listed were affected. Maybe there is more damage but many chips are protected against over-voltage.

Right now, I am trying to track down a JMC251. It seems to come in different packages, with my setup using the JMC251-LGAZ0, which is a 64 pin IC in a 48 pin package. That is, the full JMC-251 comes in a 64-bit package with body dimensions of 10mm x 10mm. The LGAZ0 is 7mm x 7mm.

It hard to say who can be trusted. I am in touch with http://www.hkwinsome.com.cn ....anyone dealt with them? There are so many scams out there.

Or can someone suggest a reliable source. I'd hate to spend big money on another power board.

The FDMC8884 is obsolete and I have been advised to try an FDMC8882, which Mouser stocks. They also stock another Mosfet that will fit the pads and seems a good replacement.

[stj]

Re: Asus k52f short

i only just noticed this thread,
why the hell did you buy something with obvious liquid damage??
and afterwards, why didnt you clean it before testing??

[gordo999]

Re: Asus k52f short

re liquid damage are you referring to me or original poster?

I was given the Asus laptop knowing it was damaged and not working. I am skilled in electronics and received it as a challenge. I have done crazy things in the past like taking a hard drive apart to see why it was not reading. I had to learn a certain amount of Russian since that's where the expertise could be located.

Different strokes for different folks.

Although the laptop is old, it has an Intel i7 processor which appealed to me.

I did clean up the area where the spill had occurred. A lot of it was in the keyboard but some had seeped through to the chip that controls the battery charge circuitry.

I checked extensively for shorts and low resistance pathways. I very carefully removed all debris and afterward the unit booted to the point where the power LED was on but nothing else.

I have taken an interest in this thread because the symptoms are unusual and identical to mine. I would have expected far greater damage and it intrigues me that only certain chips blew for no apparent reason.

[stj]

Re: Asus k52f short

i was refering to the original poster, i didnt notice it had a "new owner"

[gordo999]

Re: Asus k52f short

No point shutting down a good thread that is unresolved. If this can be solved, it will teach me a lot about the ins and outs of laptop mobos and their peculiar power supplies.

I've had several experiences with people who have taken over old threads, or newsgroups, and thought they owned them.

No fear of me going there.