BGA CPU or PCH Replacement

[caspian]

Dear technicians,

I am not experienced in BGA rework. So I have got a question.
I know GPU replacement will not last much. Despite GPUs, recent BGA CPU/PCH chips have many more tiny balls underneath (more than 1000). So the questions are:
1- How much is the success rate if a skilled technician desolder a recent BGA CPU/PCH from a donor board and solder it onto another board?
2- How long is it expected to last as a working laptop?

--- assuming the BGA chip was not faulty on the donor board.
--- also assuming the technician uses the best BGA machine.

thanks

[Seshmaru]

Re: BGA CPU or PCH Replacement

the most safest way is to get a new bga chip and new solder balls, that will give you the best result

[fester]

Re: BGA CPU or PCH Replacement

Hi,ad1: The reliability is depending from quality of the process,you must use the right balls(i change the ROHS hi-temp lead free for leaded ones),clean the board from old solder,repair solder mask if needed,use realy good flux and right amount etc..Dont forget to dry out the board and chips..The process itself take maybe 1-2 hours but you must calculate also time for drying in bake chamber- personaly minimum 6hours at 105Celsius ..

Quality of bga machine is not so important,you need only two heaters with time-temperature control and good heat homogeneity ,more important are the other things around...

ad2: If you make everything good and you ensure good heat transfer from chip then must last as long as the chip itself

[caspian]

Re: BGA CPU or PCH Replacement

I am afraid of the high number of solder balls and the tiny size of them.
I think these two factors may lead to low success rate in CPU/PCH replacement and also lead to short durability.
is this true?
So I am guessing If a technician discovers a bad BGA CPU/PCH on a board, the best way is to scrap the board. is this true?

[dellxps15]

Re: BGA CPU or PCH Replacement

got an acer 5750g with bad intel nb small bga with 0.3 or 0.35mm balls (cant remember now). removed bga, reballed with pb balls and now are 3 years pc is still fully working...

[caspian]

Re: BGA CPU or PCH Replacement

this experience encourages me to do BGA rework on CPU and PCH.

[caspian]

Re: BGA CPU or PCH Replacement

was there any short lasting BGA CPU/PCH replacement?

[ktmmotocross]

Re: BGA CPU or PCH Replacement

badcaps veteran without experience in BGA rework ?

WTF???

[caspian]

Re: BGA CPU or PCH Replacement

yes, BGA rework is mostly inefficient to invest on. specifically in GPU replacement. technician has to spend hours on BGA rework and does not even know if the chip is good or bad. mostly, no long-lasting GPU chip can be found. that is why many technicians have doubt whether buy a BGA machine or not.

[caspian]

Re: BGA CPU or PCH Replacement

has anyone experienced a short-lasting BGA CPU/PCH replacement that initially worked successfully?

[dellxps15]

Re: BGA CPU or PCH Replacement

it all depends on motherboard model and what problem there was in it.
if i got a notebook with a dead gpu, but know that nb and sb are ok, ill replace the gpu with a new one and be sure it will work like new.
as my experience most of the time when a recent notebook fails with a black screen it's pch problem instead of gpu. seen many intel nb fails insttead of gpu bad.

also many amd notebook that fails with rs780 rs880 anso got a sb problem too. replacing only the nb will not make the notebook work fine. i had to replace both nb and sb to make it back to a perfect working laptop.

the hardest part in replacing a bga is when we solder the balls to the new bga. for doing that we heat much the bga under it and if not done properly can damage bga, resulting in a non working bga after he got in place. infact when i reball the bga i decreased my air temperature from 380 to 330° celsius (atten 8586) and i always use goof flux bot for removing and for resolder the bga, as the flux stabilize the temperature under the bga

i got all the experience by examinating each time the rework done as:
1) how good solder balls and bga looks after the rework
2) at what temperature i was able to lift the bga so i know that pcb type how much heat it absorb (black pcb, blue pcb, green pcb etc etc)
3) reball the bga with as much less heat to just solder balls lead free on it without stressing it too much
4) good flux not fake or cheap
5) replace with new bga those who are known to fail when reballed

hope that helps.

[caspian]

Re: BGA CPU or PCH Replacement

thank you so much
Since I live in a small city, much BGA rework are not required here. just a few power problems per month. So it is not cost-efficient to buy a BGA machine. I believe Laptop repair is a business that belongs only to big cities.

[ktmmotocross]

Re: BGA CPU or PCH Replacement

in my experience about 60-70percent of my work in laptop repair is Reball or replace GPU, NB, PCH

so it is nessessery to have one.

[caspian]

Re: BGA CPU or PCH Replacement

I used to scrap the boards that have failed BGA chip. I should change my way and buy a BGA machine in the future.

[caspian]

Re: BGA CPU or PCH Replacement

Does anyone recommend buying a BGA machine without optical alignment camera? Can the chip be aligned on solder pads by experience without using an optical alignment camera?

actually, I want to buy ZM-R6000 which does not have optical alignment camera. does anyone recommend this machine compared to ZM-R6200?

[Pragmatiko]

Re: BGA CPU or PCH Replacement

If use a very good fluxes have 2 choose, make a good reflow or replace bga. With good reflow can get same result of reballing.

[fester]

Re: BGA CPU or PCH Replacement

Aligning the chip is not so big problem if you use really good flux.Initialy,before heating,it must be aligned maybe 1/3 of the ball diameter exactly,this is possible with good eyes and closer look at the chip and alignig marks on the board directly from top. Surface tension of the liquid solder make the rest,you can also help him with gentle tap to find the right place. Optical aligning is not necessary for 2uses/month.

[caspian]

Re: BGA CPU or PCH Replacement

I do not have much experience with BGA machines. but I am thinking now that automatic BGA machines which are mechanical machines, may get gradually out of alignment by time. I mean a used BGA machine may gradually lose its original precision in aligning the chip on solder pads.
is this true?
In addition:
is it true that a used BGA machine gradually loses its original precision in producing a heating profile so that the chip gets burned?

[caspian]

Re: BGA CPU or PCH Replacement

any experience on BGA machines losing original precision?

any experience with ZM-R6000?