CABLE, LEADS, CONNECTS
RESOURCES

Solder won't "take"

Grease or dirt present - desolder and clean up the parts. Alternatively the material may not be suitable for soldering with lead/tin solder (for example aluminium).

Solder joint is crystalline or grainy-looking

Components have been moved before being allowed to cool, or the joint was not heated adequately - possibly too small an iron or too large a joint.

Solder joint forms a "spike"

The job was probably overheated, burning away the flux. Desolder and start again, but be aware that you may have to replace the overheated components and / or cable.

Connection moves within the solder joint

Commonly known as a 'dry joint', this can be caused by several things including grease or dirt on the joint and not applying heat to the joint for long enough. Try reflowing the solder (apply the soldering iron to melt the solder over again) and if that does not work follow the instructions above against 'Solder won't "take".