I am working on repairing an Agilent multimeter. One of the ICs on the board is bad and needs to be replaced. I’ve sourced a replacement part, and am planning on swapping it out this weekend.
I’ve desoldered a number of ICs, but I’ve not worked with a relatively fine-pitched surface mount part like this before. I also have concerns about the traces and pads on this particular PCB being relatively fragile.
I do have access to a hot air station, as well as a traditional soldering iron, solderwick, flux pen etc. If anyone here feels they have some expertise in the area of SMD repair, I would appreciate any advice you can share on how best to go about swapping this part out. Some approaches I have seen are:
1. Cut the pins on the existing PLCC. Remove package, then use soldering iron to remove pins. Use solder wick to remove solder from pads. Resolder each individual pin with iron or using lots of flux and drag soldering.
2. Use hot air station to melt solder on existing part, then lift part with a pair of tweezers. Use solder-wick to clean up pads, then resolder using soldering iron (drag soldering).
3. Same as #3, except use hot air station to solder in replacement. Could I just leave the existing solder on the board and reflow it with the hot air station, or am I better off removing the existing solder?
Thanks