Soldering

[The Dotties]

I have a faulty PCB on a domestic cooker hood, which I have sourced a new replacement for. I can get at the old one to take it out and there are 7 wires connected to it.
2 of the wires are screw clamped so no problem, the other 5 are soldered into the PCB.
How difficult is it to melt the wires out of the old unit and solder in to the new one. Wires are fully accessible both sides.
Points to consider
1. I’ve never even held a soldering iron before. (New one purchased).
2. See number one

Geoff

 

[NicM]

i would suggest you have a practise go at it first, just try soldering some wires together to get a feel for it.

 

[Guigsy]

Might be worth getting a soldering project kit from eBay/Amazon to learn with?

 

[andy63]

It might help make a clean job of the removal of the wires if you use one of those solder pumps..or suckered.. it clears the solder from the joint when the iron melts the solder on the joint..
Much neater job as well..
Andy

 

[Vipar]

Have a look on YouTube your best friend

^{_{Subscribers  do not see these advertisements}}

 

[monkeybrand]

To desolder a wire connection on a pcb you could use either a "solder sucker" which is like a small spring loaded vacuum cleaner, or solder wick which is like a small lamp wick made from woven copper which draws up the molten solder. Google them, I find the wick is easier to use.

Cross posted

 

[Nirvanauk]

Make sure each surface is clean clean. Then tin (put some solder onto each surface, using the hot iron) then put the tinned wire onto the tinned connection. Apply the iron and you will see the 2 surfaces run together, remove the iron and wait a few seconds for it to cool, problem sorted. But as others have said practice first and you should find some videos on YouTube.

 

[NicM]

Just to add, you must keep the tip of the iron clean, just wipe it with a damp cloth when hot and make sure you have solder with flux in.

 

[Guigsy]

Personally I use lead based solder in a really well ventilated space. It's harder to get hold of now. But it's about ten times easier to use.

Note that it's still available for use in schools. The risk assessment says kids are more likely to burn themselves because lead free solder is so much harder to use, than the risk of lead poisoning.

 

[xsparks]

If you're in doubt why not leave the soldered wires alone and if there is room cut the wires so you can add a small terminal block.

^{_{Subscribers  do not see these advertisements}}

 

[donkey]

Does this have to done in-situ?
If it can be done anywhere I would be inclined to nip into a tv/computer repair shop or similar. It will take the about ten minutes and will be a really neat job. The risk if doing it yourself, is accidently bridging connectors with excess solder.
Not the best project to be practicing on, in my view.

Geoff

 

[TheBig1]

Shame you're not local Geoff, would do that for you as we had a coffee

 

[Gaston aires]

To desolder a wire connection on a pcb you could use either a "solder sucker" which is like a small spring loaded vacuum cleaner, or solder wick which is like a small lamp wick made from woven copper which draws up the molten solder. Google them, I find the wick is easier to use.

Cross posted

When I was an apprentice at Marconi we used solder suckers up our nose (pretend bogie suckers) just to annoy the instructor.

 

[pappajohn]

Chances are you will melt some of the insulation when desoldering.....too much heat for too long.
Probably worth snipping the wires as close as possible to the board noting which wire goes where.
Strip a little insulation off the wires then apply a little solder to the bare wire to tin them.
If the board has no solder do as above and tin the area.
Then lay in place on the board and apply a little heat until the solder just melts.
Remove iron and keep it still for a few seconds to let the solder cool.

 

[The Dotties]

If you're in doubt why not leave the soldered wires alone and if there is room cut the wires so you can add a small terminal block.

The new panel no wires in it.

^{_{Subscribers  do not see these advertisements}}

 

[xsparks]

That idea is no good then.

 

[The Dotties]

Does this have to done in-situ?
If it can be done anywhere I would be inclined to nip into a tv/computer repair shop or similar. It will take the about ten minutes and will be a really neat job. The risk if doing it yourself, is accidently bridging connectors with excess solder.
Not the best project to be practicing on, in my view.

Geoff

Agreed, but the hood is firmly fixed to the wall and the from the PCB disappear into the fan motor.

 

[The Dotties]

Shame you're not local Geoff, would do that for you as we had a coffee

Just my luck, but cheers John

 

[BouncyBoatFolk]

Photograph before starting as well, I find them invaluable and I'm constantly amazed how often I need to refer tones I've taken.
Mike.

 

[TheBig1]

Just my luck, but cheers John

If you do get stuck and can post the 2 boards and wiring down, I will solder it and post back

^{_{Subscribers  do not see these advertisements}}

 

[The Dotties]

Chances are you will melt some of the insulation when desoldering.....too much heat for too long.
Probably worth snipping the wires as close as possible to the board noting which wire goes where.
Strip a little insulation off the wires then apply a little solder to the bare wire to tin them.
If the board has no solder do as above and tin the area.
Then lay in place on the board and apply a little heat until the solder just melts.
Remove iron and keep it still for a few seconds to let the solder cool.

That is starting to sound like a plan, cheers John

 

[The Dotties]

To desolder a wire connection on a pcb you could use either a "solder sucker" which is like a small spring loaded vacuum cleaner, or solder wick which is like a small lamp wick made from woven copper which draws up the molten solder. Google them, I find the wick is easier to use.

Cross posted

I bought a “professional” soldering kit from Amazon which includes one apparently

 

[The Dotties]

Thanks everybody

 

[MisterB]

Use the smallest size tip you have to solder onto the pcb, you might even be able to file your smallest tip down? If the tip is too big it's very easy to bridge the contacts. If you can leave the contacts connected and solder onto the wires that connect to the contacts, it might be easier?

 

[Martin How]

It is (well used to be ) taught to 13 year olds in Design Technology. It's not hard, try and practice first to get the feel of it, and when you do it make sure you are in a comfortable supported position. Get some multicore solder (60/40 lead tin is easier to use but lead free is fine) and a fine tipped soldering iron. If you need to buy one I would suggest a TS100 thermostatically controlled one and an old lap top power brick (Toshiba makes it easy as the plug fits). You can even run it off the 12v in the van.

As other have said plenty of videos on you tube.

^{_{Subscribers  do not see these advertisements}}

 

[RandallC]

Take new PCB to local TV/computer/electronic repair shop and ask them to solder in wires to the colours you have on the original PCB.

Then cut off old pcb and use choc block to connect in the new one.

Overheating the PCB copper terminals & strip will damage the PCB

 

[bigalw35]

To desolder a wire connection on a pcb you could use either a "solder sucker" which is like a small spring loaded vacuum cleaner, or solder wick which is like a small lamp wick made from woven copper which draws up the molten solder. Google them, I find the wick is easier to use.

Cross posted

Get yourself a solder sucker

 

[The Dotties]

Take new PCB to local TV/computer/electronic repair shop and ask them to solder in wires to the colours you have on the original PCB.

Then cut off old pcb and use choc block to connect in the new one.

Overheating the PCB copper terminals & strip will damage the PCB

Unable to disconnect wiring from hood

 

[RandallC]

Unable to disconnect wiring from hood

No, Photo or note colours and positions on old PCB that is still in-situ.

Take NEW PCB to repair persons and ask then to solder in wires of appropriate colours into the (NEW) PCB then you can just cut out the OLD PCB and connect (now wired) New PCB to the cooker hood wires using terminal block (choc block).

No need to take anything anywhere other than the new PCB

 

[RandallC]

donkey

Thank You

^{_{Subscribers  do not see these advertisements}}