What to use in leiu of solder to connect wire to pcb with limited equipment?

[electroniclearner820327]

Some laptops have a modular board for the power supply.  This is because the power jack breaking in the manner you describe is very common. 

If the power is connected to a sub-board and not the main board, just order a replacement sub-board.

This is moot. The whole issue is I don't have access to anything at the moment!

[electroniclearner820327]

This is a critical lead I use every day: the lead which charges this very laptop I am writing this on.

It has a step down converter and one of the soldered wires broke free which I noticed was the cause of it suddenly stopping charging at all.

I am sensing a pattern here:

"My multimeter leads keep breaking."
"My laptop charger lead has broken."

Are you perhaps being excessively clumsy? Wires break if you bend them too sharply, or if you yank them, or pull on them. After you get this lead repaired, you might think carefully about how you manage to break things so much.

Correlation != causation.

That is specious speculation that it IS the cause as you are implying as a foregone conclusion.

There could be many reasons other than me being heavy handed for example, the most likely cause, that both the items in question are extremely cheap.

I am very careful with things I own thanks very much. Just because I made a couple of posts about ones I have had issues with does not say anything of the hundreds that I have had over the years and treated very well, just like I did these as best I could, and never had cause to make posts about because they work flawlessly.

[electroniclearner820327]

Why are people going off on splices in household power cables when the OP's question obviously is about a low-voltage repair on the secondary side of a power supply?

Seems things got way off course in my absence overnight! The cherry on top, 'victim blaming' me for it breaking in the first place.

Anyway I just managed to fix it.

I tried first with heating a small screwdriver and lighter which was a total fail. The lighter would not get it hot enough and I don't think it even made a dent in the solder.

Tried a couple of other metallic items to the same effect.

Next I tried with heatsink which was a success. Awkward, as I was trying to fix back a wire onto a corner terminal connection on a small pcb, but successful. I have used this same technique to make junctions on wires before. Messy but the result was a strong connection once the glue dried.

I snipped the heatshrink to make a rectangle and placed it over the corner with the wire underneath in place. I then lit it a bit, but not too much to make it overshrink and lose too much shape, then pressed down with finger. Repeat until a decent bond is made against the pcb. Gave a little wiggle and seems secure.

Dispite what the other user said about me being rough with it, I see the problem is the wires which I soldered are not held in place beyond the connection so any movement is going to put some force on the connection rather than if I say glued down the wires to the wood at the entry point to minimize the strain. It can also be because of my imperfect soldering skills, which I have done very little as usually I would be just attaching to ring connections and clamping and using heatshrink on the wire.

[ahsrabrifat]

In general, soldering is must for commercial PCBs. If it is for prototyping  like an Arduino UNO, you can include male/female/dual connectors in your design so that you can use jumper wires to connect other components to the board. Just like we do with Arduino boards.

[electroniclearner820327]

In general, soldering is must for commercial PCBs. If it is for prototyping  like an Arduino UNO, you can include male/female/dual connectors in your design so that you can use jumper wires to connect other components to the board. Just like we do with Arduino boards.

I am not saying it isn't as a general practice. People seem to miss the whole point of the thread which is that I have to make a solution with the limited tools I have with no recourse to buying more stuff.

It is like being stuck in the wilderness trying to find means to make a fire and people saying "just go to your house and cook on your electric cooker".

Anyway with it working now for the time being my attention turns to a usb/dc/battery powered solderer. I see I can get one for under £10. How come they are able to make the required heat to melt solder? I thought that making heat with electrics was one of the most costly things there are energy wise. That is why cooking on electrics is almost unheard of in the van community.

Is it just a matter of size and to heat a pinpoint to several hundred degrees is not a problem just due to the smaller surface area?

I am seeing one here that is apparently able to be powered with 3 aa batteries!

[Ian.M]

The 3 AA battery or 5V USB soldering irons are generally worthless - they just cant provide enough heat to successfully solder anything bigger than tiny pads with no ground plane or very small wires.   Smart USB C irons are a different matter, as together with a USB PD power bank capable of 20V 3A, they can provide comparable power to the tip to a mains iron or soldering station + temperature regulation.   Check the reviews on reputable tech sites before buying as not all irons are equal and many power banks cant deliver the max. USB PD output voltage and power the irons require.

You can also get 12V soldering irons with clips on the lead to go to a car battery's terminals, or a plug for a lighter socket.  They are OK, and some are capable of 60W, but they usually don't have any temperature control so you have to be pretty skilled to avoid damaging more delicate pads and traces.


Personally, I have an Orix Portasol gas iron in my toolkit, as its much easier to get a can of butane gas from just about any discount store or newsagent, than it is to recharge a USB PD powerbank off-grid without 230V AC. and its power level is adjustable.  I've had it for over 25 years, and it wasn't new when I got it.  The current equivalent model is https://portasol.com/gb/soldering-irons-kits.html?price=30-40&product_family=6

[electroniclearner820327]

The 3 AA battery or 5V USB soldering irons are generally worthless - they just cant provide enough heat to successfully solder anything bigger than tiny pads with no ground plane or very small wires.   Smart USB C irons are a different matter, as together with a USB PD power bank capable of 20V 3A, they can provide comparable power to the tip to a mains iron or soldering station + temperature regulation.   Check the reviews on reputable tech sites before buying as not all irons are equal and many power banks cant deliver the max. USB PD output voltage and power the irons require.

You can also get 12V soldering irons with clips on the lead to go to a car battery's terminals, or a plug for a lighter socket.  They are OK, and some are capable of 60W, but they usually don't have any temperature control so you have to be pretty skilled to avoid damaging more delicate pads and traces.


Personally, I have an Orix Portasol gas iron in my toolkit, as its much easier to get a can of butane gas from just about any discount store or newsagent, than it is to recharge a USB PD powerbank off-grid without 230V AC. and its power level is adjustable.  I've had it for over 25 years, and it wasn't new when I got it.  The current equivalent model is https://portasol.com/gb/soldering-irons-kits.html?price=30-40&product_family=6

What does tiny pads mean? Just small balls of solder? As these are low current dc devices that shouldn't be a problem in my case as I would only want to solder tiny couple of mm balls. It is precisely because they are so small that I use solder and just for couple of mm2 wire to pcbs for various little things like voltage step converters. For example like this: https://www.switchelectronics.co.uk/products/lm2596-dc-dc-switching-adjustable-step-down-voltage-regulator-module-4-5v-40v?_pos=6&_sid=157e55294&_ss=r

It is one like that I have fixed from the OP. Not the laptop connection to the laptop itself, but one of the wires into the voltage regulator device.

So would the 5v ones suffice for those small tasks? Bigger connections I use terminal connectors and heatshrink as mentioned above so would be redundant getting a bigger one if I was not going to use it. Will this one suffice: https://www.switchelectronics.co.uk/products/usb-powered-soldering-iron-pen?_pos=2&_sid=05d7093af&_ss=r

[Ian.M]

It depends on the width and thickness of the copper traces and wires or leads connected to the joint.  They all leach heat away from the joint, and the 10W that a 5V 2A USB iron can deliver is often not enough to get the whole joint up to the melting point of solder.  If you've got a power trace a few mm wide and a typical low voltage power lead wire leaching heat out of the joint, you aren't going to get good results with a 10W iron.  The 3x AA battery iron is particularly worthless as its max. output is around half that.

Also if you *try* to make a joint with an underpowered iron there is a high risk of board damage due to the extra time you spend on the joint 'cooking' the PCB under the pad, resulting in the pad lifting.

[IanB]

I have Hakko and Radio Shack battery irons, both of which take 4 AA cells (I use Eneloops). They work fine for joining wires and other small soldering jobs like regular PCB pads. They are nowhere near as powerful as a butane iron, and you wouldn't use them if you had other options, but as something to keep in the toolkit for emergencies, they are fine.

[mathsquid]

Hey, that's my antique soldering iron! I wasn't expecting to see it in a post today.

[electroniclearner820327]

I ended up buying one of the cheap usb ones and worked great for the small 'pads' I wanted to use it for. Melted the solder easily and job done in a matter of seconds.

Was surprised how well it worked actually.