Laptop Motherboard Repair

[Pyr0Beast]

Re: Laptop Motherboard Repair

Could be useful. Not sure where it could beat a standard multimeter.

[Setarkos]

Re: Laptop Motherboard Repair

Hi im thinking about buying leekseaker for laptop pcb board

but im afraid its gonna do wild with all the coils.

Could anyone who got that device could tell me is it a good buy for laptop pcb diagnostics.

Becouise im afraid it will be a waste of money.

[severach]

Re: Laptop Motherboard Repair

Leak Seeker

I have one but haven't figured out how to use it. I have much better luck applying bench power to a shorted circuit and see which component heats up.

[Agent24]

Re: Laptop Motherboard Repair

if you find a shorted rail - in anything,
a low-ohms meter will find the exact component real fast without lifting stuff.

years ago everybody built there own low-ohms devices - often using a speaker that changed tone.
very handy kit.

Do you have any recommendations for a design of one of these?

[Pyr0Beast]

Re: Laptop Motherboard Repair

Replace mosfets on 3.3V and 5V line and replace TPS51120

[ozer44]

Re: Laptop Motherboard Repair

Hi, i have a hp compaq nx 7400 but my laptop not charging and not power on.. i have a another problem TPS51120 very hot... What can i do?

thx

[mandacat]

Re: Laptop Motherboard Repair

Seems like a great subject / thread - anyone plan on continuing it ??

[Flounders98]

Re: Laptop Motherboard Repair

chevelle_nut

I wont have access to my digital camera until Monday, but this board is totally different from the dv6000 and 9000 i have seen before. Can u elaborate more on your repair? Do you have a schematic available? Can you recommend a replacement for the 4856a?

Thanks

[chevelle_nut]

Re: Laptop Motherboard Repair

I have a DV6500 with no power on from battery or a/c. I do have blue ring around a/c adapter. The mosfet on the top of the board near the battery connector marked pq30 is a 4856a. I measured this ic in diode mode and got 450 and 0. I have 18.5v on this ic but not on the bottom one near the power in connector. That ic is marked pq3 6679gm it reads 430 and 93. I think i will replace both, but i cant find a replacement for the 4856a. Does anyone have any suggestions on a possible replacement for the 4856a?

Can you post a picture of that area of the board? My schematics aren't matching up. I just went through this and found a bad zener as well as the 2 mosfets were needed.

[Flounders98]

Re: Laptop Motherboard Repair

I have a DV6500 with no power on from battery or a/c. I do have blue ring around a/c adapter. The mosfet on the top of the board near the battery connector marked pq30 is a 4856a. I measured this ic in diode mode and got 450 and 0. I have 18.5v on this ic but not on the bottom one near the power in connector. That ic is marked pq3 6679gm it reads 430 and 93. I think i will replace both, but i cant find a replacement for the 4856a. Does anyone have any suggestions on a possible replacement for the 4856a?

[Pesti]

Re: Laptop Motherboard Repair

Found this little Item on testing MOSFETS If anyone's still interested

http://www.electronicrepairguide.com...t-testing.html :>)

[Pesti]

Re: Laptop Motherboard Repair

Well here's a good one on the HP dv series with ffc power cables, replace them, even if they look good, The originals are crap and I personally had two DV6000 that I went thru the ringer with trying to diagnose them until I read an obscure thread on a music forum of all places, One guy said he had a friend that worked for an HP supplier, and that there was a lot of "Rukus" about a ****load of crappy ffc cables......anyway on a whim I took down one of the offending laptops and switched around the two ffc cables from the power board, since they were both the same pin count and size, and VOILA!!!~
What a bunch of crap, believe me I thought I checked the power circuit pretty thoroughly and I really thought I would have caught this...That laptop has sat on that shelf for almost a year........

[Scenic]

Re: Laptop Motherboard Repair

Sony's are unfixable unless you're able to resolder BGA chips..
most of them (like the VGN-FS215 (or was it 415?) of a friend of mine) just go dead from one day to the other.. Northbridge solder issues..

new board or more like a fixed one costs 100+ bucks.. not worth it for a Pentium M laptop.. even though they're built like a tank.. (most of the case is metal.. not plastic)

[Uranium-235]

Re: Laptop Motherboard Repair

the whole HP DV series is messed up. I've seen DV 2000's, DV6'S, DV7'S with the same nvidia chip problem. lucky we found this local iranian guy with like schematics for tons of laptop boards that fixes them for $85. he has no sony schematics though

I can fix any caps but this level of stuff I don't touch

[retiredcaps]

Re: Laptop Motherboard Repair

Acer aspire 5220 (and similar)

nVidia all in one northbridge develops a cold joint (Separate GPU is OK)

Reflow worked for an hour, then it died completely.

I just received an Acer TravelMate 2450. When the power is presed, the fan spins, the light next to the on/off button and the on/off button is lit, but nothing is displayed on the screen.

I hooked up a known working LCD monitor via VGA and still see nothing. I took out the hard drive, wifi, tried another DRAM chip and still the same symptoms as above.

Are Acer TravelMate's "known" for any type of motherboard/GPU type of issues.

[infringer]

Re: Laptop Motherboard Repair

Nice infro Pyr0Beast! thanks for sharing now we got a nice start to a guide...

Finally in our guides we should include general repair procedures the easy ones like DC Jack replacement, Monitor Replacement, HDD and Ram Replacement, Wireless Card replacement, Cap Testing, Backlight repair.... The more in depth stuff will require a scope and other things that most people cannot afford so lets stay away from things that are too in depth unless they are known problems.

Basic trouble shooting with power and POST error messages should be to apply pressure to chips related to the error mainly south bridge chips it seems then boot and see if the error still appears...

Thanks we still have many postings to go but basically we have a great start!

[Pyr0Beast]

Re: Laptop Motherboard Repair

Asus A6000

Main chip (next to the cpu) - Sis - develops a cold joint
Laptop does not display a picture when booting, it seldom boots every 10 or more tries.

Preventative Solutions: RMclock and down-volting the cpu thus reducing thermal stress.

Reflow (with lots of preheat) and it should work.

Build quality is quite amazing.

[infringer]

Re: Laptop Motherboard Repair

Known Issue: 3100/5100 Acer Motherboard

Culprit: ATI Chip on top side of motherboard

Most Common Error Message:
Bus:06 Device:02 Function:00 ERROR
Resource Conflict - PCI in slot 03 Bus:06 Device:04 Function:00 through 04 individual messages of course.

Conclusion: All PCI devices run through the south bridge of the motherboard. So looking in this region graphics and PCI devices I found BGA ATI CHIP was cause.

Action: Remove Top half of case. Look for chip marked ATI in big letters. Then get out your heat gun and repair by applying heat to it.

Video: Not Available but similar procedure video here:
http://www.youtube.com/watch?v=ctHTF3oNdxI&NR=1
Warning!!!: NEVER USE COINS TO FIX BGA CHIPS THIS IS NOT SMART AT ALL!!! But the heating principal is the only way to fix a BGA Chip with bad Balls! Unless you have it professionally done!

Results: Seems to work to resolve the issue if done correctly but is very difficult to get it just right it is not as easy as most BGA Jobs! So be warned!

Preventative Solutions: <Insert your ideas here>

[Pyr0Beast]

Re: Laptop Motherboard Repair

Compaq nc-nw82x0 series (8220, 8230)

It is a POS, overheating garbage.

Southbridge develops a cold joint (under the touchpad) and it is insanely hot.

If you hold southbridge down with your finger it boots just fine.

Preventive solutions: Don't EVER buy it.



Acer aspire 5220 (and similar)

nVidia all in one northbridge develops a cold joint (Separate GPU is OK)

Reflow worked for an hour, then it died completely.



Compaq nw800

Pentium 4 POS
Graphic card (ATI) develops a cold joint and laptop refuses to boot.
If you press down on the middle of the keyboard it will work for some time.

Workstation versions suffered even more often from this problem.


Hp-Compaq n8000 series.
Excellent machines, cold, fast and reliable. Awesome speakers, but screen somehow cracks quite often.

[infringer]

Re: Laptop Motherboard Repair

This forum is for the discussion and creation of a guide please do not ask people for fixing your laptop in this thread start a new one kindly in the laptop repair forum!

No newbies thread consider this one people are this is a joint deal to make a guide for newbies and everyone if you interrupt it with annoying little please help me fix my <insert whatever here> it may never go no where! Start your own thread!

Back to the guide I think we should make a basic known issues for certain models...

I will start it off...

HP DVxxxx is known for gpu overheating
Acer 3100/5100 is known for south bridge

We should list things in this manner:

Known Issue: 3100/5100 Acer Motherboard

Culprit: South Bridge

Most Common Error Message: Error 200

Conclusion: Laptop booting with error message 200 may need solder work on two chips on the motherboard.

Action: Preform rework with solder iron to fix error 200.

Video: http://www.youtube.com/watch?v=47PdJ5FWsQQ

Preventative Solutions: <Insert your ideas here>

Treat them as a TSB and keep in easily readable formats !!!

Now this is a start to guide creation.