Nvidia GPU chip problem

[Kujoy]

The red epoxy is a nightmare, especially when it was hand applied on the older boards. There is usually some worked right under the BGA beween balls that you cant do much about. Reworking motherboards would be a joy without it. On most boards with the red epoxy there is still the black dots of epoxy underneath, I also suspect the red epoxy made very little difference to how reliable the board was in the long run. All it seemed to do was trap more heat under the chip.

I have made a tool for removing it from a double ended dental pick. I bent the pointed tip a few mm then filed it flat so its thin enough to fit under the chip. I did each end the opposite side so the same tool can do the left hand or right hand side of the chip. I used 1500 sand paper and microscope to make sure the edges weren't sharp enough to damage the BGA chip.

I will upload some pictures if anyone is interested as I may not have described it very well for some.

I either use a hot air pen or on the jovy depending how much there is. You rarely get it all. When I suspect a chip still has epoxy under it i use more lower heat and lots of flux. Any epoxy around the balls makes them significantly harder to reflow as the epoxy insulates them sometimes to the point where they need more heat than the chip can take. Try and maintain a steady reflow temp a bit longer before you try and pull the chip (not easy with IR). The epoxy dis-solvers don't really work that well.

If anyone has better methods of removing the epoxy I would love to hear from you.

[Kujoy]

Originally Posted by koko224

What's peoples thoughts on the methods of applying flux to the chip before removal.

Do you use a mixture of liquid flux and flux paste or just flux paste?

If just paste is being used how do you get the paste right the way under the BGA.

If just using liquid flux does this work or does the liquid burn off before 217C making it useless for removing a BGA.

I'm still having issues with some BGA removal where even at 240C the chip will not move from the board, while other BGA's will remove without any problems at 217C. I'm thinking that it may have something to do with the flux, but not sure

Any thoughts?

I add a liquid flux under the BGA and let it evaporate as the board heats up leaving flux residue, this way i know 100% of the underside has a least some flux on it. Then add Amtech flux all the way round the chip. As the amtech become fluid the residue from the liquid flux actives and helps the Amtech run right to the centre of the chip. I've done comparisons with and with using the liquid flux and it does make a huge difference and can pull the chips at around 210oC.

[Kujoy]

Has anyone tried "Low Melt" made by Zeph?

Low Melt DeSolder Wire, Low-Temp SMD De-Soldering Removes Chip Quick & Easy

I really think you should check this out, especially for cleaning the BGA chip and site.

Ive contacted them to see if they have any success im getting it under a BGA. A paste version of this would be amazing.

[Dan Collins]

I use the low temp solder all the time for SMD componets, connectors, and flat packs. It is not possible to use it under a BGA. Its like working with a ball of mercury. I can't see any way to get it under the bga. Besides the existing solder has to get to liquid state and blend with this low melt stuff.
As far as the epoxy goes. A dental pick and a lot of patience is the only method I have found to work. I use BeauTech SH216 pick and a hot air pencil. Fits nicely under the BGA. Adding extra lower heat helps too when removing the BGA. The BGA's larger than 25mm are much harder to remove

[Kujoy]

I can see it making a massive difference to site cleaning and chip cleaning and got confirmation back from zeph thats it's no use to removal. Ive tried similar methods in the past like using lead solder paste and running under the chip and it just beads out.

[Dan Collins]

One more point on the Zeph low melt solder. Make sure you remove all of it before you reattach parts. It could cause the parts to unsolder during normal operation.

[Kujoy]

Thanks Dan yes that wouldn't be good.

Have you tried the zeph flux?

[Dan Collins]

The zeph liquid flux is what I use exclusivly for fluxing the BGA. Best I have found.

[Dan Collins]

I am going back to the original topic because I found something new that affects the Nvidia, or any chipset, to overheat.

I have noticed a big increase of overheating issues with laptops running Windows 7. I have found that the ability of changing the minimum processor state to a high value is burning out these laptops. Almost every one of these I have repaired have the minimum value set to 100% instead of 5%. This causes the CPU to stay at the maximum settings causing overheating issues very quickly. Windows 7 seems to be able to alter these settings automatically at some point which I have yet to determine why that is happening. Vista has the same power settings since SP1 but doesn't seem to change the settings like Win7 does.

Has anyone else noticed that laptops with Windows 7 are an issue?

[tec2004]

Hello everyone

I apologize if my English is not 100%, but you will understand ( i think )

i read all 13 pages of this thread and i'm happy with such good information, great website after that i decide register to share and learn more ( Dan Collins i like all your tips and skills you are very good thank you and all of you that post here tips about nvidia and temperature profile )

i have the zm-r5860c from Shenzhen Zhuomao Technology

i know lot of you don't have same machine and this it does not matter, i just like share with all of you the temperature profile that i received from the manufacture engineer please check all temperature profile and give me all of your comments about it. The re-balling bga in my opinion is a learning that every day we learn more and more to achieve better results

Halim_xu if you see this topic please share with me your profile i know you have the same machine with different profile i don't know why the seller provide this profile for you and the different for me ( my is provide by the engineer )

my ps3,xbox, laptops profile needed be adjust





please i accept all comments, tips, anything that can grow my skills

i also need suggestion of the temperature profile for xbox and ps3 please, i'm trying archive the best safety temperature to lift the gpu on both consoles

thank you all . peace . i will be here every day to share, help and learn..

[tec2004]

sorry for the double post but i cannot edit my last one

here is my new temperature profile provide by the manufacture engineer , please check and let me know if i can keep this or need change.

XBOX360

preheat1
top: 160 / time: 60
bottom: 165 / time: 60
slope: 3

preheat2
top: 190 / time:35
bottom: 205 / time:30
slope:3

activation
top: 210 / time: 40
bottom: 255 / time: 30
slope: 3

soldering1
top:225 / time:90
bottom: 280 / time: 200
slope: 3

soldering2
( don't need for xbox) only ps3

down:
top 190 / time 30
bottom 190 / time 30
slope:4

[Trion]

Originally Posted by Dan Collins

I am going back to the original topic because I found something new that affects the Nvidia, or any chipset, to overheat.

I have noticed a big increase of overheating issues with laptops running Windows 7. I have found that the ability of changing the minimum processor state to a high value is burning out these laptops. Almost every one of these I have repaired have the minimum value set to 100% instead of 5%. This causes the CPU to stay at the maximum settings causing overheating issues very quickly. Windows 7 seems to be able to alter these settings automatically at some point which I have yet to determine why that is happening. Vista has the same power settings since SP1 but doesn't seem to change the settings like Win7 does.

Has anyone else noticed that laptops with Windows 7 are an issue?

Is this on Intel's core series processor based laptops or older chip based laptops? Have you seen this on a working laptop that hasn't had settings messed up by customers? Because this can be done by a person over-riding default settings in windows 7 that affect individual core performance, but haven't heard of this happening automatically.

[Dan Collins]

Trion,
This was on AMD based mobo's. Now I cannot vouch for the setting, but I have been seeing this on laptops that have been running high end gaming, which I do not reccomend for laptops, and believe the games are turning on performance features that Windows 7 seem to accomodate and earlier OS's didn't. What I am seeing is on these laptops that come in is the power settings set to max. The customers swear they didn't even know about the setting, but in every case it was high graphics games and Windows 7 that did it.

I have found no way to fix this since Windows 7 allows ACHI control to these games. Customers don't like hearing that there are some programs that should not be used on these laptops. This is a real dilema for us repair guys.

[Dan Collins]

tec2004,
The zm-r5860c seems like an advanced version of the Bird 5000. Looks like it uses a combo of hot air nozzles and IR. I read the manual and it seems like it uses the full temp control capabilty of the module unlike the IR and BIRD which only has preset limited functions. Not sure I can compare or use your settings since my systems do not have that level of temp control. Did you get the camera option? Not sure that would be very useful unless it could see under the BGA. Maybe you could see when the BGA self aligns itself. That could be handy. Neat machine. Keep us posted as to your results.

[Nicpoe]

Originally Posted by Dan Collins

PU8 MAX8724 is the batt charger chip.
Also suggest replacing MOSFET PQ57 SI4914DY

This is assuming an AMD board

Change these two Components fix the battery Problem? My dv9000 does not charge any battery, the led blinks already.