How much force would you say you applied to pull the heatsink off? I would think that you'd have to pry pretty hard to damage traces or solder joints under the chip, or you'd have pry with a metal tool that gouged\scraped something.

Without knowing how experienced you are at soldering, I would say it's more likely that one of your solder joints isn't good enough. Getting a good solid joint on through-hole caps on nice multi-layer boards like that can be surprisingly tough unless you do a lot of soldering or have a really nice setup. Preheating the board helps a lot since they can absorb a ton of heat compared to older boards.

If you have a really good magnifier, check each solder joint, and apply a tiny amount of force to the cap to rock it back and forth (tiny amount!) to see if the joint moves.

Also, check inside all of the slots, and brush off the front and back of the board thoroughly to make sure there aren't any conductive contaminants causing problems.

EDIT: Also, it's worth mentioning that if a heatsink is stuck on with any kind of thermal epoxy, it really shouldn't need to be repasted because the curing\drying process happened before it even left the factory, so there are no concerns of the paste drying out over time or thinning out and pumping\flowing out from the contact area.

In this case, since you were able to actually get it off, it was probably just paste. But even if it's just stuck on really well with paste, I think the benefits of pulling it off and reapplying thermal paste on most hardware are greatly exaggerated. In most cases I wouldn't bother doing it unless it's a part that's known for getting heat damaged due to dried out paste, or if it's a part that's really hard to access normally and you've already got it partially disassembled.

I cannot find the Panasonic "CAP" series/type...
https://industrial.panasonic.com/ww/products/ … cap-lead/models

Sometimes the old thermal paste gets hard so the heatink is glued to the BGA chip. If any solder balls have deteriorated due to age, heat or a non-optimal production process it´s indeed possible to loosen them when pulling the heatsink away from the chip/mainboard.
You can try if the error persists when you press the heatsink and chip down firmly during startup.

There are more caps than just those 8 you replaced on that board. It's entirely possible other caps have now become the weakest link, such as the medium-sized ones near the DIMM slots.

That said, checking your solder joints and pressing down on the chipset heatsink as already advised are definitely steps to try before soldering any more.

I have enough experience to competently solder through hole capacitors and I did check and reflow the solder joints. I think maybe I did something to the North Bridge because it was glued. It's ok though, this was a more of a fun side project. Everything else still works fine.

Sly_Botts wrote on 2023-01-24, 15:11:

I have enough experience to competently solder through hole capacitors and I did check and reflow the solder joints. I think maybe I did something to the North Bridge because it was glued. It's ok though, this was a more of a fun side project. Everything else still works fine.

It's better to heat a glued heatsink before removing using a usual hair dryer. After heating you won't have to apply too much force to remove the heatsink.
Though there's glue that doesn't get softer after heating. In this case I push a knife with a thin blade between a chip (not a bare die FCPGA !) and a heatsink.

Every now and then, when I´m in a hurry, small sprinkels of liquid solder drop down and slip under an ISA-, PCI- DIL- or a memory socket so they cannot be seen.
Each time it´s quite an effort to find them...

My hands are getting worse as time passes, like if they were bad enough, I damaged an A7N8X deluxe 2.0 because I damaged on trace on one of the two capacitors on the left side of the memory slots, and now, the board only recognizes the memory on the first slot.
So maybe other caps on your board are bad, and it may be interesting to try to recap the rest of the board, after all, at least my board was plagued with OST capacitors.

Hoping wrote on 2023-01-24, 16:50:

My hands are getting worse as time passes, like if they were bad enough, I damaged an A7N8X deluxe 2.0 because I damaged on trace on one of the two capacitors on the left side of the memory slots, and now, the board only recognizes the memory on the first slot.
So maybe other caps on your board are bad, and it may be interesting to try to recap the rest of the board, after all, at least my board was plagued with OST capacitors.

You know... I guess I could try that, just replace the caps next to the memory slots.