CPU socket replacement soldering profile

[Geomih]

Hi All - I am hoping someone can help with some pointers (complete noob here!)

I have recently purchased a Scotle HR460 BGA reball machine (it's a bit old and I think the company no longer exists either), but as far as I can tell it is a competent and unmolested machine that should be good enough for my needs.
My biggest problem is that it came with no profiles, and I must re-create all of them from scratch, something that is very scary for someone that doesn't really know what they are doing.
The simple stuff like a small memory module isn't a big deal because there are a few example profiles in the manual – but for more than that the manual is no help as it is very basic. Also, it does not contain any of the advanced features, so I have no idea if the fan speed that is programmed in is fast or slow or if it needs to change based on the application.

Primarily I bought this style machine to do socket replacements on AM5 and LGA1700 boards, but after what looked like a promising start with a profile that worked well for desoldering, I am afraid I might have become overconfident and ruined a Strix Z690 board as the same profile was not OK for soldering a new socket back.
This is the complete profile that I used:

The last number in the corner that is in glare is 250C.


Unfortunately, I am not 100% sure how the board died, it still turns on at it doesn't trip OCP, but all the diagnostic LEDs stay off while before it would show that it got stuck on RAM (the missing pins were RAM-related). It might be that I overcooked it or when I tried to turn it on first time it had an internal short and that was that. Regardless with nothing to lose I un-soldered the CPU socket again and it was immediately clear that only the corner balls had melted and made good contact while all the others were untouched. I do not believe the board is warped so I don't think that was the issue. I have read some older posts on here with someone else complaining of the same issue, I don't know if they fixed it or not - I did send them a PM.

At this point I am just hoping that the test CPU and memory did not get damaged in the process…I will know for sure in two days' time when I get a new motherboard delivered as instead of buying a Celeron or something I used an I7 13^th gen for testing.

Does anyone have a similar machine and have you developed your own profile that you know works for various applications? Obviously, a socket soldering profile would be amazing but even a 50 x 50 GPU or large SMD profile I think would be immensely helpful in diving what sort of settings I need.

I can set 6 stages for my machine and the temperature, rate of climb and hold time can be set independently for the top heater, bottom heater and additional IR heaters.
The other advanced parameters such as fan speed and segmentation parameters I do not know how to adjust so I left them alone – if they are the same as they left factory, or the previous owner has changed them I have no way of knowing. I was tempted to factory reset the machine hoping that the profiles would show up, but thankfully I checked online, and it seems other people that have done that ended up with a “blank” machine without any software so I won't be doing that.

Sorry for the long post and thank you for reading!

[jasko_jacker]

From the specifications I saw that it has an air top and bottom + IR bottom. However, if it has a top IR and a bottom IR, the profiles change.
In general, if you have to replace the plastic socket of the CPU it is very important (do not apply this rule to BGA chips) that the profile is as slow as possible because we are not interested in keeping it within certain time limits but we are interested in the temperature rising slowly. in order not to damage the motherboard it is important that the temperature of the part under the socket (bottom layer) does not exceed 205 210 degrees centigrade (in the final phase of the soldering process when the top also interferes) while as regards the temperature of the top obviously it must not be lower than the melting point of the alloy used (remember that it is important to place one or two thermocouples near the socket which must touch the board and must be placed in such a way that the air is not directed, some machines refer to the temperature of the air and not of the card and this must be considered). For this type of intervention, however, air is better than IR due to a question of heat absorption also linked to the color of the socket. The process should last no less than 6 or 7 minutes. if you tell me what type of top and bottom you have I can try to recommend a profile or how to create it.

[Lisa Su]

This might give some insight on LGA1700 socket replacement.

[Geomih]

Thank you so much for the replies and insights Jasko_jacker and Lisa Su - I can't tell you how much this helps for someone like me who starts from a complete blank slate and please be patient if any of my questions/thoughts sound ridiculously naive (its because they are..).

Jasko_Jacker - my machine has a 800W top heater, a 1200W bottom heater and 2700W IR heating elements all around. Unfortunately it does not have any optical aliment, but i am hoping i can get around that with careful placement.

Again - any help and tips are greatly appreciated! Also with regards to applying the solder paste on the motherboard - any clue?

Lisa Su - The manual is amazing - i am shocked as it seems i am missing the curcial step of applying solder paste on the motherboard (!?!) I am so confused about this one because the socket comes with balls pre-applied; do the sockets that OEMs use not come pre-balled?
It sort of makes sense to put solder paste on the board, but i am worried that could create blobs when the socket balls and solder paste both melt.
The sockets I got look like this:

Each pin is balled, but I did notice that the balls do look like to be barely sticking below the plastic ribs and was a bit worried they would not make contact - if i needed to bridge the gap with 0.5mm solder paste it would make a lot of sense 🤦♂️. I did a quick google search and found LGA 1700 stencils, but no AM5 ones.
I liked the bit at the end about socket storage and handling - all the sockets I ordered came wrapped in tissue paper!


At the moment i am on a technical break and can't experiment because while trying to tinker with a profile i set the rate of climb to 10C/s instead of 1C/s and this happened


The bottom 1200W heater simply exploded (it was quite spectacular - large orange whoosh and sparks). I did manage to get it out of the machine after some ticnkering and ordered a (hopefully matching - at least the dimensions match so it shoudl fit + its the right wattage, but the coils look completely different which i am hoping does not matter as they have the same rating) replacement and now i am waiting for it to arrive from Aliexpress.

[diif]

No, don't use solder paste. You don't have the space.
Watch this https://www.youtube.com/watch?v=Tal1Isw-HUQ