Nvidia GPU chip problem

[frida0231]

I bought RE7500,,and interested in the experience and sugestions abaut repair Nvidia GPU chipset in laptops??
Your suggestions and repair tips are welcome,,

[gbluez]

Hi,
I dont have RE7500, but sometimes i work on pc part.
All computer part now days are fully ROHS compliant. The lead free tin bga is so hard to be reworked.
Try to find some documents about it on google.

[mp3team]

I bought RE7500,,and interested in the experience and sugestions abaut repair Nvidia GPU chipset in laptops??
Your suggestions and repair tips are welcome,,



hi. I use t870A , buy the re7500 jovy I received this week. . repair laptops. I would like to share my experience. with the nvidia gpu. the
G6150
Annex photos of my work

http://rapidshare.com/files/234637026/photos_hp_tx1000_remove_gpu_nvidia_g6150_.rar.html
.
my English is not very good

greetings from COLOMBIA

[paisleypcdoc]

Just finished reflowing the nvidia gpu on an HP DV2500 using the jovy.

Just used the standard Jovy leadfree profile and PLENTY of foil tape protecting the plastic components on both sides of motherboard.

Worked perfectly 1st time.

If a reflow doesnt fix it, remove and reball with lead based solder and re-attach with a lead based solder profile.

If that still doesnt work, the chip is duff. Remember to check whether replacement chip has lead or lead free balls and use appropriate profile.

Obviously, if you dont have equipment to reball, you need to go straight to replacement.

-Michael.

[mp3team]

Just finished reflowing the nvidia gpu on an HP DV2500 using the jovy.

Just used the standard Jovy leadfree profile and PLENTY of foil tape protecting the plastic components on both sides of motherboard.

Worked perfectly 1st time.

If a reflow doesnt fix it, remove and reball with lead based solder and re-attach with a lead based solder profile.

If that still doesnt work, the chip is duff. Remember to check whether replacement chip has lead or lead free balls and use appropriate profile.

Obviously, if you dont have equipment to reball, you need to go straight to replacement.

-Michael.



height that you use? , Upper Heater for not leaving the blistering chip.

[paullovinicius]

hi. I use t870A , buy the re7500 jovy I received this week. . repair laptops. I would like to share my experience. with the nvidia gpu. the
G6150
Annex photos of my work

http://rapidshare.com/files/234637026/photos_hp_tx1000_remove_gpu_nvidia_g6150_.rar.html
.
my English is not very good

greetings from COLOMBIA


please, can you upload it again???
the limit for download was reached.

thanks

[Trion]

I reflowed an HP pavilion DV2000 with geforce GO6150 successfully too. Its working fine for around a week now. Have asked customer to use with laptop cooler and not to run it on games for more than 45 mins as the heat transfer system is horrible. Have reflowed another today with a GEforce GO 7200. Shall be putting it together and testing it tomorrow. Another great use for RE-7500! This is one moeny making machine.

For those who are interested, i used the upper heater at lowest position. And its not just profiles. You have to keep an eye on the board. Sometimes manual control is best when it cmoes to reflow.

[Trion]

The second laptop too is working well. Am doing some cooling mods to keep the chips cool as HP has made a very bad cooling design using a thermal pad to transfer heat from the chip to the heatsink. The chip should have been in direct contact with the heatsink. Thermal pads are ok for RAM ICs and northbridge chipset ICs provided they're not GPUs.

[pentu]

hi. I use t870A , buy the re7500 jovy I received this week. . repair laptops. I would like to share my experience. with the nvidia gpu. the
G6150
Annex photos of my work

http://rapidshare.com/files/234637026/photos_hp_tx1000_remove_gpu_nvidia_g6150_.rar.html
.
my English is not very good

greetings from COLOMBIA

Hi,
Can you upload your photos again
Thanks

[pentu]

I reflowed an HP pavilion DV2000 with geforce GO6150 successfully too. Its working fine for around a week now. Have asked customer to use with laptop cooler and not to run it on games for more than 45 mins as the heat transfer system is horrible. Have reflowed another today with a GEforce GO 7200. Shall be putting it together and testing it tomorrow. Another great use for RE-7500! This is one moeny making machine.

For those who are interested, i used the upper heater at lowest position. And its not just profiles. You have to keep an eye on the board. Sometimes manual control is best when it cmoes to reflow.

Hi Trion,

I have ordered Jovy RE-7500, can you share your experience of using jovy RE-7500, it will be great for future users.
Thanks

[uncleseb]

Hi,
Can you upload your photos again
Thanks I am interessed ( i buy it very soon), can you upload again please
many thanks

[mp3team]

I am interessed ( i buy it very soon), can you upload again please
many thanks



ok
http://rapidshare.com/files/261643921/photos_hp_tx1000_remove_gpu_nvidia_g6150.rar.html[/URL]

pic remove g6150 t-870a

[URL]http://rapidshare.com/files/261643195/jovy___g6150.rar.html (http://rs483l3.rapidshare.com/cgi-bin/upload.cgi?rsuploadid=336349831319402978)

thanks

[Trion]

Hi
I have now fixed 5 laptops successfully so far. The models are: HP DV2000, Dv6000, and COMPAQ V 3000. besides the reflow, you MUST remove the thermal pad that is in between the GPU and heatsink and replace it with a 2mm thick copper piece approx measuring 7x8mm. These laptops all fail because of the thermal pad not being able to efficiently transfer heat to the heatsink. So just reflowing the GPU isn't enough. Also use arctic silver thermal paste on the GPU, then place the copper piece on it, again put a little more paste and finally fit the heatsink on this. This way you will have a 100% successful repair that will last for a long time. Use this utility to check GPu temp: GPU-Z. get it here: http://www.techpowerup.com/gpuz/

if your GPU is runnning normally at around 60 degrees or less, that's ok. And when running games it shouldn't be more than 75-80 degrees. If your GPU crosses these temperatures, you can be sure the cooling is faulty and needs modification. Check the temp even on working laptops in the DV2000, 6000 and 9000 series and compaq V 3000 series.

I had one laptop whose GPU temp would shoot upto 90 degrees in a few minutes. After the cooling mod it starts at around 49-50 degrees compared to 85.

While reflowing the GPU, i use the default Jovy Lead free reflow profile for the NVIDIA GPU. Do make sure you bend the temperature probe tip as recommended by JOVY to get correct temp readings while reflowing. The upper heater is to be kept at the lowest height for this reflow and reflow of most large BGA ICs. In case your machine isn't following the profile, either heater height is wrong or temp probe isn't making proper contact. Once the reflow is done cool the board and do the cooling modification with copper pieces and put back the laptop. And your laptop should work. If not you may need to reflow again as i had to in one case. The reason for this was i hadn't used flux the first time. I generally run the machine for a few minutes on preheat and place the board onto it and start the profile from a temp of around 45-50 degrees.

I use AMTECH flux.

I have given you the info you need to be successful in repairing all the laptops with this kind of problem.

Good luck in your repairs!

[linears4]

i repaired several hp dv series, but no way to fix it permanently with a normal reflow, they fall after a couple of months,

i think that in these hp model they don't use normal unleaded balls, but some kind of high temperature alloy, cause removing is very very hard.

jovy 7500 has no sufficient preheating area for these boards and a proper reflow will never happen, you can test during the work if the reflow is well done by trying to move the chip during reflow with a small tweezer, if touching it very gentle you can see the chip moving then the reflow is doing properly, if you feel the chip steady on the board during the reflow process, no real reflow has happen, and no long term repair will succed.

the reason why the board work after this kind of work is that the balls make good contact cause thermal dilatation, but after a medium time it will stop working again.

for a permanent fix , reballing with leaded ball 63/37 is necessary, and then you can do the modification with a copper shim to prevent failure in the future.

[Trion]

I agree with linears4 about a reballing with lead based solder being the better solution. And its true that just a reflow might not be sufficient.

[linears4]

yes, the problem is the unleaded alloy itself, soldering alloy used originally in hp dv series is a very hard alloy, and that suffer a lot during thermal cycles during the working of the laptop, day by day, during these thermal cycles crack easily occurs due to the hard nature of the alloy. this happens also because the chip is not cooled properly due to badly designed contact with the cooling pipe.

leaded alloy is much softer, and less sensitve to thermal cycles and it does not crack easily. of course, improving the contact of the chip with the coling pipe will add more reliability too.

[ian8115]

Been reballing now for a while but frustratingly still getting returns. Not sure if it is inadequate cleaning of PCB tracks, wrong flux or poor quality solder. Using Lead free but what is the best leaded solder? Reflowing HP laptops I have found is a waste of time and 90% will come back within 12months. Most within 2 months.

Thanks

[linears4]

reflowing on that model is not a good thing.

you are experiencing returns on amd or intel model? or both?

if you use jovy machine for the work, absolutely avoid pre programmed thermal profiles... they don't let you to set a very important parameter, the TAL (time above liquid) , if the tal is too short, as in the pre programmed profile, the solder joint will not be reliable.

and also, the thermal ramp is gotta be adeguate, if the temp raises up less than 1,5 centigrade per second, the solder joint will be unreliable too.

and last but not least... i suggest you to use only new bga chip from factory.

why ?

i've done many researc, and in many cases, in the nvidia chips, the defective part is the flip chip itself . The flip chip is the little square at the center of the whole bga.

the flip chip is bonded with the substrate (the green part of the whole chip) exactly like a bga... yes, it has under itself many hard alloy spheres, about 200 micron diameter....

when you do reballing or reflow you are going to heat this small connections too, so, the chip will work for that reason... and even if you do a perfect rebballing and soldering on the board, thi chip will fail in the future cause the problem are not the balls between bga and board( second level connection) but are the small connection between the flip chip and the substrate(first level connection)


many times the problem is this, other time the problem is the second level connection, but it is impossible to figure wich kind of fault are, so replacing the chip with a new one it is the best deal.

[Dan Collins]

Hi,
linears4, what TAL do you use?
I must concur, that we are dealing with the pcb reflow only and the breakdown may be under the chip itself. That would most certainly explain the 50% success rate with these nVIDIA chips. But it is difficult finding replacements for some of these. I can find the 6150, but not many other models in new stock.

Anyone out there have a good source for other NEW nVIDIA chips like the NVS-110 or the G86-620?

I have another related question for the experts out there. Would it be better to strip the lead free solder off a new chip and replace with leaded balls? I assume the new ones have lead free.

Dan

[linears4]

i use 70 second for the small chip about 25x25, max 90 for the bigger chips about 35x35. avoid to go furter, too much high TAL will do the solder joint brittle.

i alaways take off the unleaded solder balls and put a new set of leaded ones. But just to avoid problem with unleaded soldering process. Making a good and reliable solder joint with unleaded balls is a very hard challenge. if you intend to use the original unleaded balls you have to bake the chips before the installation, if you fail to do so you will certainly have some internal delamination due to the higher temp. The moisture trapped inside the new chip will damage the chip itself, even if it appear perfect after the soldering process.

from the other hand, changing the original solder balls will add a thermal cycle to the chip, increasing the chance to damage it or to make it unreliable in the future.

bga and mcm rework it is a very hard thing...


good result is the combination of many many factors

[linears4]

i have 100% welding success, with any kind of chip until 35mm, but only at zero time, zero time means after the welding process.

my biggest problem is the long term reliability.

in some cases the chip fails again after about 6 months. in other cases i have some chips working even after one year.

i'm trying to figure the cause, but it is very hard.

i know too that if i fail to do baking i will encounter some problem, but baking process is very time consuming.

a must is to bake the new chips, for 8 hours at 85-95 degrees at least, and then make a moisture barrier package. the theorical floor life of this kind of components is maybe 72 hours, after that a new baking is needed.

but very time consuming process.

even the whole board has to be beaked, to avoid cracks in it during welding.

but all this is a crazy thing...

but a thing is shure, only reflow will never give a long term reliability, cause you don't have flux on the pads, and a reflow can't change the penetration of the soldering alloy to the metal pad, it can only adjust a crack, but if the problem is on the interface a reflow can't change the things too much

[Dan Collins]

linears4, are you suggesting that baking is important for any embedded chip due to moisture? Interesting conclusion. Sound like there are a lot of factors to take into consideration. I will start doing some research on my own. My Brother-in-law is a solder paste chemist. I will run some of this past him and post any findings

Tnx

[linears4]

yes, expecially with multi module chip and lead free, all the graphics chips today are multi module chip, whit flip chip on it. Bga's are completly different thing, on the construction side.. for example, southbrige intel 82801 series are bga... nvidia gf6150 are multi chip module's. all the black plastic chips are bga... the green ones like nvidia and ati, but even intel northbridge are multi chips.

baking is not my conclusion, there are ipc standards that say that... j std- 033 and so on..

bga are less sensitive by moisture, multi chips are very sensitive to it... if you store the chip in a moistured enviroment the moisture will damage internally the chip during the soldering process. maybe the defect will be latent and will come out after many months.

[Dan Collins]

Oh, I see then, for me here in a very dry desert climate and all components stored in AC enviro, the moisture concern is minimal.

My RE-7500 arrives in 3 weeks from Jovy rep in Flordia. I have been doing BGA work for years with other methods. Really looking forward to using the infrared. I have spent many hours reviewing posts and videos and have a pile of junk boards to do much experiment on before I put system in production. That is why many of my questions get into specifics.

I do have a question regarding use of RE-7500 that is not clear in posts I have read, and that is the height of the upper heater. It would seem to me that the goal is to supply heat that comes as close as possible to the setting and T/C readings as possible.
What is the optimal height setting for the RE-7500? Does it vary for different tasks?

TNX
Dan

[laptoppartes]

hi, i own a small laptop repair shop in el salvador, central america. i have been fixing this issues with the classic hot air gun. i recently read a GREAT story from the inquirer explaining the cause of the nvidia bga problem. i must say that u guys are doing a great job giving your techiques to many of us who are interested in fixing this motherboards. my technique right now is the usual heating of the chip for about 90 seconds at aprox 150F ata a distance of maybe 2cms. then we place a copper piece for it to make contact with the heatsink. but as u may imagine the customers come back sometimes after 3 weeks, sometimes after 2 months. i have been web-searching a system to cool down the gpus and i found a thermoelectric cooling system wich uses a small plate with one hot side and one cold side (peltier cooling system), this morning i bought my first thermoelectric system at a price of $6 on ebay and will receive it in 7 days and i cant wait to receive it...i will certainly post the results here.
someone was asking for a website to buy the chips i found some in alibaba.com...i purchased 2 f500/f700 motherboards from them and im satisfied.

[linears4]

no, no absolutely no! if you want to do reflow only, you have to see if you have done it correctly! you have done only a chip heat... if you want to do a reflow, you have to rework the chip , and you will have to check if the reflow is done properly. for doing so you will check with a tweezer if the chip become loose during the reflow process..

in other words you have to check if the solder balls will liquifiyng during the reflow, for doing that you must to tap the chip on the side, to see if the solder balls reached the liquifing zone.

but as i sayed , reflow is a waste of time, it does not add reliablity

there is no way to do so with an hot air gun, believe me or not... you need power, and at least you need a good infrared or hot air station. you need preheat, there is no chances to melt the unleaded solder balls with a simple hot air gun

[laptoppartes]

thx a lot for your help.
my question is now why does heating chip temporarily fixes the problem, if the solder isnt liquified with the heat gun, why does work? and i also have another question and is if the cracked solder balls are between the silicon chip and the substrate( not between the substrate and the motherboard) why does everybody focus on the motherboard-chip area?

and one last question...why does the wireless card stops working before the video goes out?

thx a lot for your time and responses

[Dan Collins]

laptoppartes - I have used alibaba, but I never get a reply from the sellers.

Sometimes the USB ports also goes south before the video.

And I think you answered your own question as to why the short life on repairs because you do not reball. I would be interested on your conclusions from the thermoelectric heat sink mod.

Thanks

[laptoppartes]

thx for your response. what i actually meant with my first question was to know what effect does heating the chip has, cuz it does help a little, when i do this repairs i only give the cust one month warranty on the repair, i charge between $30-$50 depending on how good is the customer (regular customer or stanger). if they dont answer you in alibaba is probably because they are in china and they are all sleeping right now. the msn of my seller is hpmotherboard@hotmail.com, she is a nice salesgirl. as i was saying, i purchased 2 f500/f700 motherboards from them at about $105 (shipping not included) , they are used but they work

[linears4]

thx a lot for your help.
my question is now why does heating chip temporarily fixes the problem, if the solder isnt liquified with the heat gun, why does work? and i also have another question and is if the cracked solder balls are between the silicon chip and the substrate( not between the substrate and the motherboard) why does everybody focus on the motherboard-chip area?

and one last question...why does the wireless card stops working before the video goes out?

thx a lot for your time and responses


solder carcks doesn't mean a gap of miles...it means micron level gaps... when you heat the whole chip, thermal dilatation of the balls occurs so these micron gaps are temporary gone away... and the connection is almost restabilished due to the termal dilatation of the heated balls.

but, successives thermal cycles of the chip during the working create various dilatations of the solder balls. the balls increase it size, and decrease it size day after day, hour after hour.... but the crack is there, so when the gap become newly too big... game over... no working motherboard.

the cracks are not alaways between the chip and the substrate, there are no simple method to figure where is the crack, only a scanning acoustic microscope can tell the true, but we all human mortal can't even touch those kind of diagnostic machine...

so we can only think that the crack is between the chip and the motherboard and do reballing...

this is the reason why it is advisable to use new chip.

or, if we have various similar fault whe can have a statistical approac... trying to reball the faulty chip and look if the work last


response to the last question :

the wireless card stops working when the faulty chip is the northbridge, not the video card. for example on hp dv series with amd processors.

when the northbridge is going out, the first sign is the lack of the wifi functionality or other types of faults not correlated with the video section.

when the northbridge is totally out , black screen occurs, but not due to the video chip, but only due to the northbridge chip, that controls the video chips too.

[Dan Collins]

TNX, I will give them a try. Looked into the TEC and seems to me as though you will not be able to control the quantity of heat that it will generate with the small fan/heat sinks that are in the laptops. may need a controlling circuit. Sounds like a lot of R&D to me. Good luck.

[linears4]

on compaq f500 for example, the video chip is embedded in the northbridge chip, (nvidia g6150) .

on inte lcore2duo based machines the wifi never fails before the video section because the northbridge of these machine (intel 945-965) is very strong and never fails. the only fails happen is the grafic nvidia chip, in almost cases due to fan clogging

[linears4]

forget peltier cooling... you will be in trouble with a lot of moisture that will liquify on the cold side of the plate causing shorts when the drops rheach the motherboard.

[laptoppartes]

great, i never thought the northbridge was the cause of the wifi problem on the hp amd systems. everything i have learned to do is due to experience and webresearch. my associate has an electrician degree but he doesnt have a clue on this hp issues. he taught me how to heat the video chip and he thinks the wifi issue is caused because the "lane" (i dont know how do u call this in english, but i actually mean the electric path on the motherboard) of the wifi goes in the same video chip lane. so by heating the video chip he fixes the wifi issue. he will be surprised when i tell him about the north bridge problem. by the way do u know how much temperature can the nvidia video chip resist? what is the hottest i can get without burning it? and regarding the problem with the northbridge: does it have to be replaced? or just heated?

[linears4]

i don't know exactly, you have to look to the datasheet if you can find it.

i think something about 250 degrees celsius, but only if the chip is stored with a maximum percentage of moisture of 10%.

increasing the moisture level , increasing the chances to damaging it by popcorn effect even at lower temp

[Dan Collins]

Wifi is on the PCI bus, so whatever chip controls that would be affected. My guess would be the GPU is not part of that circuit.