MAXIM chip failure - Repair or just replace motherboard?

[techpitt]

Is the Maxim chip a BGA? I'd be surprised. If it's not, reflowing won't fix a thing.

I'm pretty sure it is QFN. May I ask why reflowing is innefective on all but BGA chips? I'm still reading up on the matter, but my understanding is that reflowing is just melting the solder so that voids get refilled and then the solder solidifies again. Is it the amount of solder available to reflow on BGA that makes it effective vs. the relatively small amount available on a QFN?

Ah well. I've plenty of QFNs on practice boards to pull up and try putting back on if there is no other way.

 

[Larry Sabo]

It isn't likely to be effective in my view, because the solder joints are not likely to be the cause of the problem. The reason BGAs fail is because of the expansion/contraction of the solder balls with heating/cooling and the lead-free solder having poor ductile qualities. That is, they shear or develop micro fissures under the stress, rather than expand/contract. With QFNs, there is a large heat sink beneath the centre of the chip, which dissipates the heat to the MB, and I suspect the contact areas are larger than for BGAs, which further reduces temperature stress. With BGAs, the heat path is very long, the thermal pad doesn't do as good a job as a direct contact to the package, the CPU is dumping heat into the heat pipe and then the GPU, and the QFN doesn't have a probably-blocked radiator that reduces heat flow. Anyway, that's my understanding of the two and why I say I doubt a reflow will do much good.

 

[techpitt]

Thanks for sharing your experience, Larry. Your explanation of BGA and micro fissures match up pretty well with what I suspected from what I've read on the subject. It is nice to have the voice of experience confirm and expand on it, though.

I'll likely do a proper resolder once I get my hands on some paste and have a few practice runs, but I'm going to try a reflow just for kicks since it doesn't take long and is currently within my skill/equipment's capability. I don't think heat issues directly are what caused the problem (as you'd find with BGA), but I think the ambient temp inside this laptop chassis contributed to the issue, with the main cause of failure being that the Maxim chip sits right by stress points on the motherboard (DC jack, screen hinge, D-Sub port). Laptop overheats, shuts down, then frustrated user slams screen shut which flexes the motherboard and stresses the weakened solders.

Whatever the case, I'll update this thread as I learn so that other techs aspiring to component level repair may benefit from it... particularly if they have a "Toshiba m35 HP NC6000" or other model that frequently encounters this failure. ( :

 

[NYJimbo]

... particularly if they have a "Toshiba m35" OR "HP NC6000" or other models that frequently encounters this failure. ( :

Fixed it for ya.
..........................

 

[techpitt]

Fixed it for ya.

lol... wondered if you'd catch that.

 

[BCS Head Tech]

I'm pretty sure it is QFN. May I ask why reflowing is innefective on all but BGA chips? I'm still reading up on the matter, but my understanding is that reflowing is just melting the solder so that voids get refilled and then the solder solidifies again. Is it the amount of solder available to reflow on BGA that makes it effective vs. the relatively small amount available on a QFN?

Ah well. I've plenty of QFNs on practice boards to pull up and try putting back on if there is no other way.

Hello, I guess you fixed this issue but I had a question for you about your question or statement rather? You stated that "May I ask why re-flowing is ineffective on all but BGA chips?", are stating that re-flowing is only effective on BGA chips?

The reason I ask is because re-flowing is a band-aid fix period, there is no way to guarantee a repair you never know when it will fail again. It could be 1 day, 2 weeks, or 3 months, you just never know... QFN's are fairly simple to replace if you have the right tools. To answer one of the other questions about having enough solder, if you use a good flux(RMA) you wont have to add solder on a QFN, but remember it is still not removing the lead free solder whcih is going to be a better fix. Sometimes based on time, we will re-flow a small component verify that it works then remove it and clean and re-solder with lead solder.

The proper way to re-flow is to use RMA flux, some people don't even use flux but that is not the proper way. Solder flux helps to spread heat evenly through the joint as well removing oxidation and or contamination.

In addition QFN"s only have leads on the perimeter of the chip and most are small, so they are typically easier to do than BGA chips. BGA chips have approximately 300-800+ balls varying in different sizes.

Hope this helps, if you have questions this is what I do everyday. You can IM me at pci.tech.

 

[ell]

Thanks for the input everyone, and sorry if i misinterpreted your tone, Jimbo. I've Google'd and Youtube'd the subject in the past and will definitely take more than a few practice runs before trying the maxim. I'd still appreciate any links to good educational reources for the beginner, and suggestions for inexpensive equipment for someone who is serious. I can go on newegg and buy a $20 iron with some tips, but will that even come close to being useful? At the same time, I'm hoping to avoid the $200 irons if that is overkill.

I guess the answer to my initial question is to just replace the motherboard and sell the laptop to finance the purchase of soldering equipment so i can learn and practice and turn the next free laptop around for more profit. Lol

P.s. the keyboard on my phone is wretched! Sorry for slow replies and typos.

I've been in business 6 yrs and don't do soldering jobs. My spouse and I have replaced two power jacks for our kids and it took us quite a while on each! We were successful...finally, but I would have never done it on a customers machine. Everything always looks easy from a youtube video until you try it yourself. I can't say I wouldn't like to learn this skill, its just that its just so seldom I need it and just don't have the time to learn. If you have the time and machines to practice on, go for it!

 

[techpitt]

You stated that "May I ask why re-flowing is ineffective on all but BGA chips?", are stating that re-flowing is only effective on BGA chips?

The reason I ask is because re-flowing is a band-aid fix period, there is no way to guarantee a repair you never know when it will fail again. It could be 1 day, 2 weeks, or 3 months, you just never know...

...

Hope this helps, if you have questions this is what I do everyday. You can IM me at pci.tech.

Hi BCS, thanks for the response. I understand that re-flowing is just a band-aid whereas lead-free solder is the wound, but seems like it can be a bandaid that might last for the remainder of an older computer's useful life. By saying "ineffective", I meant only to enquire about whether or not reflowing would have any effect (permanent or otherwise) on the failed solder of packages other than BGA. I actually haven't attempted repair of the laptop in any fashion yet because when I sat down to take it apart, I realized that my kitchen table just wasn't cutting it. I've been focused on getting my home office ready so I'll have a nice quiet safe haven from my toddlers in which to work. Once I get back to practicing, I will likely take you up on your offer of assistance!

I've been in business 6 yrs and don't do soldering jobs. My spouse and I have replaced two power jacks for our kids and it took us quite a while on each! We were successful...finally, but I would have never done it on a customers machine. Everything always looks easy from a youtube video until you try it yourself. I can't say I wouldn't like to learn this skill, its just that its just so seldom I need it and just don't have the time to learn. If you have the time and machines to practice on, go for it!

I can't fault you for that... things that look easy on YouTube are often harder than ell! (sorry, I couldn't resist!)

I'm not sure how often I'll get soldering jobs, but I had a flurry of opportunities for DC jack replacement recently that I had to decline because I lacked the equipment and skill. I hate turning jobs down, especially of this nature. Beyond being almost pure profit, I can imagine scenarios where someone brings a laptop to me with a few years on it and decides that it isn't worth the expense to fix the DC jack and opts to just buy a new one. This is a good opportunity to offer free or discounted services (such as data migration to their new laptop) in exchange for the old hardware which will likely just get put into storage or thrown away anyway. Pop in a new DC jack, run diags to make sure nothing else is wrong, nuke, pave, re-sell, and have one more PC out there that may eventually come back for virus removal or the like. This is a win for everyone.

Off topic- my basement workshop/office is almost done! So much more work went into it than you can tell from these pictures... Won't be long until I can get back to practicing soldering and start going full throttle with the home business. I'm very much looking forward to posting finished pics in the 'show your workshop' threads.

 

[ell]

LOL, nice pun...not. yes, thats basicly what I do when I get a power jack issue, most places charge $100 plus there is no guarantee once they get in there the motherboard isn't cracked too. I sell my data transfer/set up pkg and help them purchase a new machine. As far as fixing and selling, tried it once, put it on ebay as "AS IS NONWORKING" and a guy who bought it then threatened bad feedback cuz the mobo was bad, I won't sell anything used now, plus I don't have time to fix em.

 

[acesdeals]

maxim ic are usually qfn chips which means they have pads at the end of the chip but right underneath it and usually another in the middle

you would need a rework machine as there is no possible way for a soldering iron to get to it

there are usually 2 maxim ic that are faulty as well the regulator goes out on occasion

the chips are tiny and surrounded usually so put some kapton tape around the chip so other components dont get moved