Disassembly of HP-19C

[teenix]

Assuming the soldering iron is hot enough and the tip size is adequate to supply the required heat, one way to get it to melt is to have some melted solder on the tip so heat transfer can take place and hold it (not too long) on the place you want to repair. You can add a bit more solder when the tip is in contact with the soldered PCB surface to help transfer the heat.

If it does melt and you have too much solder remaining on the joint you can remove some with solder wick.

If the solder "blobs" on the joint, it may be an indication of contamination (oxidation or dirt) in the old solder or component leads, or not enough heat from the soldering iron.

Avoid too much heat though, or you risk damaging the component, PCB traces or through hole vias.

Bear in mind also, that some components (IC's) are sensitive to static discharge so care should be taken to avoid damage when handling PCBs or during repairs.

cheers

Tony