I am adding a extra fan to my xbox but when i try to solder the wires under psu motherboard the solders on the pin won't melt or flow in order for the wires to connect. I have a 40watt soldering iron and its working fine and i tested it so what seem to be the problem??

thanks in advance

Maybe your tip on your iron is not clean. That's why the solder might not be heating up. And to solder to the pins under the mobo, you have to hold the iron on there a little longer since it is lead free solder.

the solder iron is brand new so its clean

I was holding my solder on the pin for 1 min and still won't melt . I kept cleaning the tip with the stainless brush and adding fresh solder on the tip before heating the pins. I have lead free solder and it melts it easy but still don't understand why i can't melt the solder on the pins.

Brand new doesn't mean tinned, clean and ready to use, just means new.

Flow a little bit of new solder on to the solder joint and leave the iron on there a little longer. The 12v and Ground planes there are kinda heavy and the heat takes a little time to build up. The new solder you add will aslo help to transfer the heat from the iron tip to the solder joint and help to get it all to reflow.

thanks rdc, how long would it take to heat up? its not gonna take over one min to flow right? and leaving the solder iron tip on the pins to long could damage your motherboard?

I find its best to tin an iron when it's heating up, else it just drips off and doesnt stick to the tip.

If it's not reflowing before a minute then ya need a bigger boat. If it's not reflowing the solder ya can leave it on there all day and it's not going to hurt anything, damage happens when ya have too much heat on a trace/pad that's already reflowed and ya continue to leave it on there anyway. Those joints there really do take a good bit of heat to reflow, and if your iron has a temperature control on it then turn it all the way up (just for this kinda thing) or toss another iron on there as well.

ok i heat up the joints and applied fresh solder and it wont even melt, i heated it so long i felt the motherboard was hot. I have the pencil type tip for my iron and its not cutting it so what type of tip should i use?

Use the flat chisel tip. It has a wider surface area to heat up the pins.

do you need clean the joints before soldering?

Joints of what? Just go get a bigger tip for your iron, and get some flux and some stuff to tin your iron if you dont already have it.. tin your iron, and then apply some flux to the pins, and then try to add solder once your iron is hot.

hmm... this is weird. it only takes me less than 2 seconds to reflow the solder on the 12v and ground pins. i use a 30 watt pencil tip too. all i can say is get a better soldering iron and make sure you tin your tip properly

Wow, I've soldered to those with a 15 watt before... are you sure the iron's working correctly?

Yes it is working i tested on a pc motherboard and easily melts the solder joints. I think the newer model motherboard is harder to solder? please correct me if am wrong.

Please recommend any good soldering iron and is cheap because i only gonna use it just once for my xbox.