"Antony Gelberg" wrote in message
...
Hi,

I know this should be simple but isn't. I need to resolder a DC power
connector on a laptop, due to dry joints.

I can't find my old, rarely used soldering iron, so I went to Maplin
and
bought their cheapo 30W soldering iron.
http://www.maplin.co.uk/module.aspx?...32909&doy=13m6

I would have thought that is good enough for PCB soldering, but I can
barely
get the old solder on the board to melt, let alone re-solder the
joint. I

Hello:

The why's of your problem have been explained by other posters.
You can solder your dc jack with your 30 watt or the pistol, better yet,
get a friend and use both, however, there is a trick to it: you have to
preheat the pcb.

To do so, get a hair drier, set it on max and slowly start heating a
large area of the board from a distance of 20cms (8inch), then start
aproaching and concentrating on the jack, it takes about 5 minutes to do
it properly, your board will be very warm overall, then heat the board
directly above and bellow the jack with the hairdrier nearly touching
them, do this for about 3 seconds each side, repeat about 4 or 5 times,
then and only then use the solder iron to remove the jack, if you have a
friend you can use both irons, the pistol on the ground connection the
other on the other pins. the jack should fall off. be very gentle with
the pistol if you use it, because the board is allready hot, such beast
will easily damage it if you aproach it like you did when it was cold.

P.S: to use the pistol *first* heat it enough to melt solder *then*
touch the parts then turn on-off-on-off at about 1Hz.

Best regards

Steve Sousa