redjay1:
But when the chips were down and I had to replace the power port on my laptop I had to run down to maplins and pick up a 50w iron to melt the solder adequately - up to that point I thought that solder was solder and any old iron would do (pardon the pun).
I think you had to deal with lead free solder there. Leaded solder melts at 180 C, but while common in DIY, it is no longer allowed in consumer products. Lead free solder has different compositions, but the melting point is usually around 220 C - so you will need more heat to unsolder it.