I've got a chromebook from years back that I still use--decent enough processor, decent amount of RAM, and it's got Windows 10 loaded onto it with the help of a custom BIOS/firmware.  That being said, I also have a dead laptop laying around that has an i7-5500u processor in it, which blows my chromebook's celeron processor out of the water in terms of speed.  I'd like to put the i7 in my chromebook.

Just to preface: the celeron 3205u and i7 5500u are hardware compatible: they share the exact same Ball Grid Array socket, they share the exact same 15 watt TDP, and they share the exact same Intel architecture generation (broadwell mobile).  I even emailed a guy that makes custom firmware for these laptops and he told me that (in theory) there would be no problems swapping these CPUs and they'd be fully compatible with each other.

Only issue is, these are Ball Grid Array CPUs as mentioned before, so I can't just pop it out of a socket.  I need special tools and skill to make it happen, which I don't think I have.  Therefore I want to explore the possibility of paying someone else to do it to ensure it gets done right.  Only issue is, a lot of reballing websites seem kinda sketchy.  So I was wondering if anyone here had any experience with a certain type of business that does this, and they could refer me to them.  Ideally the less expensive the better, but if there's a slight premium to pay for a person with a good reputation I'll take that into consideration.

EDIT: before anyone says this... yes I know this is stupid to waste money on a low end POS laptop like a chromebook.  But this is my beater machine that I throw around, and would like to keep using it if possible.  The reasons why I want to do this are as follows:

1. Because I can


2. Because then it would be Hackintosh compatible if I wanted to go that route


3. Because then I'd get AES hardware acceleration for Full Disk Encryption


4. Because the slight increase in clock speeds would work wonders for HD video streaming

This guy has a YouTube channel. Seems to do good work. But specializes in macs.  He does have the proper machine to reball though. Maybe shoot him an email.

https://www.rossmanngroup.com

All I have to add is:  LOL!



ETA: unless you live in Chengdu or Taipei, in which case you can probably bribe one of the guys in the local debug lab to do it for you!

You are aware that pretty much every single CPU for the past 15+ years requires specific microcode load support in BIOS or firmware to be supported?
"Simple" family, socket and TDP compatibility is usually not enough. It's specific enough that even a stepping of the same CPU SKU may lack support on a motherboard that supports older steppings, without a firmware update.

It is highly unlikely you have microcode in your current BIOS to support the i7 5500u, or that you could lay paws on the microcode to support it, and unless you're a firmware hacker able to modify the chromebook firmware to add support for the i7 5500u, even having the microcode wouldn't be enough.

So I thought the same thing, but I emailed the guy whose firmware I'm running right now.  He goes by MrChromebox online, and he specializes in making open source firmware for these things (it's a modified version of Coreboot).  He's real familiar with the hardware and firmware that goes into these things, and he told me that in this scenario there would be nothing stopping this from working, so long as I was running his custom BIOS/firmware (which I am).  The other hardware, such as the embedded controller, would also be fine with it.  It even appears that this model of Chromebook shares an embedded controller with the 2015 Macbook Pro, and that thing can run 5th gen i7's just fine.

The cool thing about Coreboot open source firmware is, from the looks of it, you can specify which CPU microcode blobs to load in on boot (you don't build the blobs yourself, they're provided by Intel).  He assured me that the CPU microcode he builds his stuff with would be compatible with the 5500u, but if I needed to I can just rebuild firmware/BIOS again with a different microcode blob included.

But hey, at the end of the day, if it doesn't work then I'm only out about $30 (plus reballing cost) because that's all this POS is worth on eBay anyway


Thanks for the suggestion, can't believe I didn't think of this... I used to watch this guy all the time

What the hell is a heat sync?  Oh, I get it, you’re the wizard Mac repair shop but you have heat sync confused with heat sink.

That inspires confidence

Some of those places that repair phones do reballing on phone CPUs.  There is at least one guy creating youtube videos.

Considering the size difference it might be a really easy thing for them to do.

His website also used to say that they repaired iPads, but when you send them an iPad to be repaired they tell you they don't work on them.
Attention to detail doesn't seem to be their thing.

I can swap BGA chips but there's no way it makes sense, financially, on a laptop. It's the sort of thing I do for scientific equipment and development stuff where the cost of replacement is huge or replacements just don't exist. It takes a lot of time, some specialized soldering equipment and there's always risk no matter how careful I am.

The last time I did it was a few months ago. I swapped an FPGA out on a clients oddball project because they couldn't wait for Chinese New Year to pass to get a new board made and assembled. There was a bunch of other stuff on the invoice, but the swap probably cost ~$400 in labor plus whatever the mask and new part cost them (they sourced all that).

I'm sure there are guys out there that'd do this sort of thing for less, or a six pack, but I don't know how to go about find them. I'm all for hacking hardware too keep old computers out of the landfill, but you're going to need to be real thougthful about how much this chromebook is really worth to you.

the problem with swapping CPU's is generally not the reballing or the site cleaning.
the problem is getting the device down and down reliably given the amount of ground plane area under modern BGA CPU devices.
the big ground planes suck heat away from the device, which can compromise attachment reliability.
without a 5DX machine you will not be able to look at the ball geometry after reflow.
could it work? of course.
if it doesn't?  odds will get worse, not better with repeated attempts.

ref:
https://www.ar15.com/forums/outdoors/on_the_modern_methods_of_post_assembly_inspection_of_ball_grid_array__BGA__device_attachment/22-675740/