Here’s a video of how to remove an SMT chip from a board with a minimum of work and fuss.
Without knowing how to do this, it’s easy to damage pads on the board, break pins, overheat other components, etc.
But, with a slightly different method, it’s pretty simple.
We’ll be using an air embossing tool.
(I have this one… )
First, you heat up the whole board a bit otherwise you can damage nearby components via thermal shock.
Next, heat up the chip in question until the solder melts on ALL the pins.
Then, use tweezers to lift off the chip.
At this point, you’ll still have an adequate amount of solder nicely on the pads and therefore we won’t be using any solder.
Set the replacement chip down, align the chip and then align the pins, and use your iron to tack down ONE pin.
Then align all the rest of the pins and tack down the diagonally opposite pin.
Now solder them all into place.
While I’m thinking about it… The important thing here is to warm it slowly and then be fairly targeted with the heat. Mine is hot enough to damage the board or chips and plastic housings. So keep it in motion.
I think any of them will work, but you need to be careful to not just heat a single place. Keep the gun in motion and then only touch the chip you care about. Adjacent parts will have their solder melt as well so you need to not touch them with your tweezers.
and putting the other chip back on.
If you took the chip off like I describe above, then you have solder already on the pads on the board and you shouldn’t need more.
all you need to do is place the chip in the correct orientation and then tack down the pins using the iron.
start with diagonal opposite corner pins, then tack all the rest.
sorry you can’t see half of the pins being tacked down, but I couldn’t figure out how to hold the chip in place and show it on video at the same time…
A different method changes the whole ball game doesn’t it.
Check the large pad after you remove the old one. If I remember correctly, the large one on mine didn’t have quite enough solder on it. Add the solder to the pad, then tack down the chip as the video shows.
Nice! Back in 02 I overclocked my Titanium Powerbook to 550Mhz from 450. Had to move a resistor on the logic board. I was quite pleased with the soldering, even if I did do it with a cheap pencil iron with no temp adjustments! No way I could do that today without a magnifying glass…
Since Google are being dicks about photos, I’ll just post a link, can’t just stick a picture here anymore…
