Before taking an iron to your Raspberry Pi, download and install an OS image on a microSD card and confirm that the system boots successfully. If it refuses to run in this state, we can troubleshoot and replace the board if needed. This is your last chance…once modified, there’s no telling if a failure was from the factory or a result of your board work.
Dismantling the Raspberry Pi is extra challenging, even if you have prior desoldering experience. Lead-free solder requires higher temperatures, and this board’s substantial ground plane draws away a lot of heat. But apply too much heat and you’ll rip up traces or delaminate the board!
The conversion process is made a little easier by just not trying to salvage the parts being removed! Don’t hesitate to clip leads, or completely dismantle the metal port housings. Anything to better access the area you’re trying to desolder. Let it go.
There is no One Right Way™ to do this. The process should be adapted to your own particular skills and tools on hand. Even with a wealth of tools, it’s still pretty time-consuming and may take a couple hours.
Before proceeding, you can optionally let the board cool off, insert a microSD card and test whether it still boots. Without USB ports you won’t be able to connect a keyboard and shut down cleanly, so don’t do this with a card containing irreplaceable data.
If the system won’t boot…or if it does boot, but the red power LED is flashing, disconnect power and look over your desoldering work for any bridged connections, or conductive detritus that may have been scattered on other parts of the board.
Once it’s fully cooled, try attaching a monitor and booting the system from a microSD card. If the transplant was a success, you should be able to connect a USB keyboard and log in.
The red “PWR” LED should be on steady. If it’s flashing, there’s an electrical short or a damaged component somewhere.