Component Level Motherboard Repair (Not replacement)

I've been fixing computers for a while and more and more recently, I've been seeing ads from people claiming to do component level motherboard repair and not just DC jacks. (ie badcaps, mb repair).

This is something I really want to learn about because sometimes a replacement motherboard is rare or too expensive to fix. Some questions I have:

1) How do you diagnose the exact component failure?
Obviously, a burn mark is a dead give away, but what if there are no visual signs? Do you poke around with a multi-meter? With what voltage settings and how do you know what to look for?

2) Is it usually a bad capacitor?
badcaps seems to think so. What about a bad connection?

3) How do you perform the component level repair?
So you've found the bad capacitor or component, can you really solder a new one on without hurting the components around them? What's a good soldering iron for under $100?


For those of you that do component level repairs, any thoughts on this are greatly appreciated.

 

Yes, it is usually a blown capacitor. It's easy to diagnose as the top of the capacitor will be bulged upwards, and sometimes even leaking (yellow/white corrosion on the top). Any chips that burn are usually ICs, which are too delicate to replace without expensive robotics that will do the soldering (not to mention the high number of contacts on these chips).

Those websites are very old, look at the pictures. Those are Socket 7/Socket 370 motherboards. When motherboards were much more expensive, this was worth doing. Now, with motherboards (and all components) being so cheap, this is only worth doing for personal use (as in, if you can fix your own board for 5 bucks then it's worth it, but if you want to do this as a service, not so much considering what the price will be after labor). The other thing is almost ALL motherboards (and video cards) now use solid capacitors, which do not have this issue.

You can really do the replacement. I've done it before, you just look up the specific capacitors, order new ones (I use Mouser - http://mouser.com/), desolder the old and resolder in the new. I also use desoldering wicks to pull up the solder from the old component. If you'd still like more information, despite my advice against this route, I'd be glad to help.

PS- Your website is broken, clicking home links leads you to a 404.

 

question, Hep. Are you near sighted, by chance? Because I am and it helps me greatly with soldering.

(404? on New Orleans Computer Repair???)

 

http://neworleanscomputerrepair.com/new-orleans-tech-support.htm
http://neworleanscomputerrepair.com/new-orleans-computer-repair.htm

Click the home links just below the nav bar. Wow. Just... just wow.

 

No, I have 20/20 vision. Capacitors only have two contacts over a comparatively (compared to other components) large area, which makes them extremely easy to replace.

 

And there's usually only what, 10-20 capacitors on the average MB?

 

It really depends on the board, but that sounds like a good estimate. Not all will always need to be replaced, though if you have bulged/blown caps it's a good idea to replace them all, or at the least replace all with the same rating. I also find that though they can blow literally anywhere, the ones that go most are the ones that usually are in a line beside the CPU or memory.

 

The voltage on your multimeter... Is it relative to the cap?

 

Sorry... how are you testing anything but continuity on a capacitor? They don't really hold charge long enough and if you test with the system on I think you are risking damaging the system. I could be mistaken though...

To answer your question yes, you choose the voltage closest to what the expected output should be.

 

1) How do you diagnose the exact component failure?
Obviously, a burn mark is a dead give away, but what if there are no visual signs? Do you poke around with a multi-meter? With what voltage settings and how do you know what to look for?

2) Is it usually a bad capacitor?
badcaps seems to think so. What about a bad connection?

3) How do you perform the component level repair?
So you've found the bad capacitor or component, can you really solder a new one on without hurting the components around them? What's a good soldering iron for under $100?


I may be able to answer your questions, because I have undertaken laptop component level repair in last 3 years.

Diagnose problem:
This is the hardest part in notebook repair. Basically, we measure voltages on motherboard and there are few power supply range from 1V to 12V on the motherboard. For example, north bridge needs 1.05V, 1.2V, 1.5V, 1.8V, 2.5V, depends on model of north bridge.

We also measure all sort of signals, such as PCIRST, CPURST, CLK. We measure the resistances of each AD line from north bridge to CPU/RAM.

We watch the current changing patterns to get rough idea where is the problem.

There are some simple steps to follow when check a notbook motherboard:
1. make sure main system powers are ready, that is 3V and 5V.
2. switching circuit is ok, which involes IO/Keyboard controler, south bridge
3. power sequence is ok, which you can see the current jump up and down for few times.
4. all the necessary signals are not missing.

About Bad Cap,
It happens but only about 10% in those motherboards need to repair, and it is the easiest fault to repair not matter if the cap was burnt or not.

Loose connection,
Mostly happen on VGA chips, south birdges and the places close to CPU. Hard to troubleshoot and need lot experiences.

How to repair?
You need specialised tools. I have DC power supply which can display current change and set to different voltage and current output. Really nice soldering station, SMD rework station, BGA rework station, etc. I also have more than thousand schematic diagrams, all together about 10GB and you could not find anywhere in the net.

I have seen the video in youTub teach people how to fix IBM T40 VGA problem, and I guess you only have 30% chance if you follow it. My BGA rework station can perform up to 95% successful rate.

Component level repair is not easy to learn, I have destroied at least 200 or 300 motherboards due to vary mistakes.

 

Wow, what an informative first post,
welcome to nbr,

Do you work at a motherboard repair facility?
cause we can relay those with bad motherboards to you, since you have the know how and tools.
I have some motherboards which have failed, and if you service them or have the diagrams, you would be a very important resource for nbr.

I have similar equipment, but my knowledge is only from experiment and trial and error. I managed to fix my D900K board three times already in the past year, two of which requiring me to make soldering mods to the board, and one was a rebuilt circuit for a fan header I blew by mistake.

K-TRON

 

I use to work in a company to fix notebooks, but I am running my only business specialised on fix notebook on components level.

I wish I could get business from you but unlucky I am in Australia.

I have fix few D900 board few month ago, not easy to fix. They use too many PWM chips that not often see in other laptop.

I think I could start a new thread and put my repairing records on the net, so people can see the depth of component level repair.

 

I would love to have a copy of those schematics for laptop motherboards. Do you have a link or any way that I could them? Or could you tell me how I may get copys of them?

 

Hi all! (Sorry for my basic english)

I have a Clevo D900T, and it doesn't start. The screen stay black, and the ventillators doesn't rotate. This is classic motherboard death, i know. I have electronic-experience, SMD soldering etc. The main Volrage regualtor wich regulate the CPU voltage (called Synchronous Buck Controller) ADP3188. On the CPU tantal puffers i see wrong signal i think, it is same as the positive half period sinus after positive half period sinus.
The normal switching frequency is ca. 330kHz, but i hear maybe 10kHz "beep" when i turn on the machine. The switching Mosfet's get warm few secound, and the phase inductors too.(Lower frequency do this maybe)

Can anyone help me in this problem? I know you are great specialists
Sorry for my basic english

Thanks for your help!

 

Sorry inductors are inductivity naturally

 

sounds like you need a new motherboard. I did soldering work on my D900K board (AMD version) and it worked for some time.
You may want to check out this website:
They have the D900T motherboards for pretty cheap:

http://www.ztronics.com/motherboards.html

Just make sure you buy a motherboard which has the same version number. The version number is crucial for video card compatibility.

K-TRON

 

Hi K-TRON!

Thanks for the tipp! They have reasonable price. Shipping to Hungary... maybe.
Everybody sucks with these intel motherboards. This is something typical error, i think. I read everything on the net, but can't find the real problem (component level) Before buy a new mobo i'm going to try repair the old one.

The CPU voltage regulator has 16 swithing MOSFET, they working (in an good mobo too) extremly hot. Maybe this FETs toasted, or the driving circuit.

Anyone know the secret of this super, but problem child?

Thanks!

 

Hi jialinc, do you have and email add or ym? Thanks

 

Hi Guys,

Would anyone know how to go about repairing faulty USB ports? I have a travelmate 8005 and 8006, both of them have faulty ports, and the cause on both of them were mobile phones, just yesterday i connected a W960, the screen started blinking, had to hard reset, after powering on again the CMOS reported bad checksum, reset the cmos and got in windows, but since then none of the usb ports are working.

The laptop works fine apart from the usb, would anyone have service manuals/schematics for the TM8000 series? Any help would be greatly appreciated.

Best regards.