Resoldering Power Connector

[mnewsome]

All:

Much thanks for the thorough replies. This is a Dell 4000 laptop. Is there any way to determine the soldering composition from the model? Continued guidance sought.

Going to attempt to resolder the power connector to the board. Is there a particular solder composition i.e. tin, lead, etc. that is the preference? Guidance sought.

 

[nukemaster]

Thin flux(helps it stick better) core should work(like you get a radio shack).

I would be more worried about the iron being too warm and melting other contacts since they are close to on another.

Hope your hand is steady.

What board is it? a desktop ATX connector? Laptop power(at least easier to solder once the board is out)?

 

[fieronv]

What you need to look for is a symbol stating if it is ROHS compliant. IF you see ROHS on the board or if the solder is dull grey it is lead-free solder.
Lead-free solder needs special care when soldering. It takes more heat to flow than tin/lead solder. You will need to evacuate the old solder on the board not just reheat the solder. Industry standard for lead free is SAC305 96.5% tin 3% Silver 0.5% copper. You will need a soldering iron that will reach temperatures abov 750 degrees F and a good flux that is made for lead-free solder (higher temp). Also realize that lead-free solder does not flow as well as tin/lead solder and it will be dull grey when finished. Most motherboards made after July 06 are lead-free due to the EU mandates for new products.
It is very important that you DO NOT use tin/lead solder with lead-free solder doing so can change the melting temp of the solder and cause major problems!

 

[rasco_matt]

To be honest I’m not sure exactly what solder you should use.

What you need to look for is a symbol stating if it is ROHS compliant. IF you see ROHS on the board or if the solder is dull grey it is lead-free solder.
Lead-free solder needs special care when soldering. It takes more heat to flow than tin/lead solder. You will need to evacuate the old solder on the board not just reheat the solder. Industry standard for lead free is SAC305 96.5% tin 3% Silver 0.5% copper. You will need a soldering iron that will reach temperatures abov 750 degrees F and a good flux that is made for lead-free solder (higher temp). Also realize that lead-free solder does not flow as well as tin/lead solder and it will be dull grey when finished. Most motherboards made after July 06 are lead-free due to the EU mandates for new products.
It is very important that you DO NOT use tin/lead solder with lead-free solder doing so can change the melting temp of the solder and cause major problems!

However I don’t agree with this recommendation. Why not use common 60/40 tin lead solder with flux core. Using the above recommended solder requires extreme temperatures, which could result in a damaged board. Just remove all old solder with solder wick replace the socket and solder with everyday solder using an everyday soldering iron.

 

[fieronv]

The reason you can't mixed lead-free and lead solder is the addition of lead to a joint that has been soldered with lead-free solders can change the melting temperature of the joint to under 120-130 C this can damage the board and parts also the lower melt temps can allow the parts to fall out if the temperatures around the joint get hot enough for the solder to soften up. The other issue is the brittleness of the joint. If a board has been manufactured to use lead-free the board and part are designed for the higher temperatures.
This is something I deal with daily at my job. I had to do all the research and training to get my company ready for the switch over to ROHS. To say the least I don't like lead-free solder, it is not proven technology. Lead-free solder is very brittle and there is another problem with it as it can grow tin whiskers that can cause other issues. There are a couple of industries that are exempt from the ROHS standard these are military, aerospace and medical I personally wouldn't fly in a plane that had lead-free solder in the wiring.

 

[rasco_matt]

How much do you intend on spending for this repair...?
Do you have access to or own all the equipment that you may need...?

If you are not skilled in soldering and you choose to use solders that require high temperatures, you may end up damaging the board. I have seen people screw up solder joints and pcb's using standard 60/40 tin lead solder. I would assume that the power connector's joints will not be subject to extream temperatures during operation.

If a board has been manufactured to use lead-free the board and part are designed for the higher temperatures.

Boards and components may be designed to handle certain temperatures during the manufacturing process but this usually doesn't take into consideration a heavy handed person with an extremely hot soldering iron.

Do you think that your soldering skills are up to the task...?
Does this job need to be built to a standard or does it just need to get the laptop up and running..?