Well, it has been a long day, but Project Oxcart (with Aaron, Ross, and
Wayne) has now reached its conclusion. We spent from 3 pm to 11 pm today
in the EE building soldering room, and successfully transplanted the new
TSB41AB1 chip we bought from Digikey for $5 each. The EE people have a
complete set of really cool soldering gear which helped us with the job.
The firewire controller chip was damaged by a voltage surge, so while the
chip still functioned on the PCI bus it could not talk to any external
devices, making it useless. Dell wanted to charge $1100 for a replacement
motherboard, so other alternatives were obviously sought.
We completely separated the Dell 8100 into its components, and put the
motherboard under the microscope. Due to the size of the component, the
entire operation was performed under the microscope. We used a hot air
pencil to heat each pin, and then a dental pick to lift up each pin,
careful to not rip up the tracks underneath. Once all pins are lifted up,
the chip then just falls off (about 5:30 pm). As you can see the chip is
very tiny with a fine pin pitch. The tracks on the PCB were then cleaned
up to remove any solder and to prepare for the new chip. Fresh solder was
applied to the pads and then cleaned up to ensure that not too much solder
was present. The new chip is then overlaid on top and carefully aligned,
and the iron applied to melt each pin onto its pad. After each step the
results were inspected multiple times to check for solder jumping tracks,
stray solder balls, and that all the joints were properly implemented.
Note that while this sounds simple, each step took a number of hours and
was very tedious. I have attached a number of photos that we took of the
process from start to finish.
At about 10:30 pm, we reassembled the laptop, and then plugged in the
firewire camera, and it worked perfectly the first time! We took a photo
using the web cam on the firewire port - Project Oxcart is therefore a
complete and total success!
So it *is* possible to repair your computer if you blow something up :)