Laptop Lead Repair?

[TheJay]

Hey everyone,

I have a laptop charger cable, which has snapped after being flexed numerous times.

Can someone please tell me what the large plastic bit is and whether it's possible to cut the cable down slightly and add a new DC connector?

Thanks.

 

[Lightium]

What plastic bit? Circle it because it's all plastic to me.

 

[TheJay]

 

[Lightium]

Yes you need that or one like it.

 

[Nigel Goodwin]

I would disagree - the circled part is likely just a ferrite 'bead', and removing it will not make the slightest different - as long as the OP can buy the exact correct sized plug, and fit it to the cable, then all should be fine.

 

[Lightium]

I know that they are inferior to one's you can replace it with, but I would keep it.

 

[Les Jones]

The "Plastic thing " is a ferrite bead filter to reduce RF radiation from the power cable. If you cut the plastic coating you will be able to slide it along the cable.
(The computer will work without it.)
You may have a problem obtaining a connector of the correct size as many commputer manufacturers use non standard connectors.

Les.

 

[eTech]

I would disagree - the circled part is likely just a ferrite 'bead', and removing it will not make the slightest different - as long as the OP can buy the exact correct sized plug, and fit it to the cable, then all should be fine.

I disagree.
It will still “work”, but not reliably under all conditions. The filter wouldn’t be there if it wasn’t needed in the first place. I’d keep it.

 

[Tony Stewart]

two hemi-cylinder ferrites are selected to raise the CM impedance of the ripple current in the SMPS charger. They are molded together with plastic. All VGA cables have this , but only some Laptop chargers have these to reduce the CM noise in microphones and other sensitive peripherals.

 

[Nigel Goodwin]

I disagree.
It will still “work”, but not reliably under all conditions. The filter wouldn’t be there if it wasn’t needed in the first place. I’d keep it.

It's there to give a small degree of noise rejection under extremely rare circumstances, and it's almost impossible that anyone would notice it's absence.

It's also pretty difficult to try and leave it where it is, as there's VERY little space to try and fit the cover from a manually fitted plug on the wire.

 

[TheJay]

The charger pin size is 7.4mm, is that what you were referring to having difficulty matching? I'd prefer to add a right angle DC connector rather than like-for-like.

 

[Nigel Goodwin]

The charger pin size is 7.4mm, is that what you were referring to having difficulty matching? I'd prefer to add a right angle DC connector rather than like-for-like.

The difficulty is is you have to slide the cover over the wire - as there's not much wire left before the ferrite bead. And finding the correct sized plugs is always an issue, as there are so many different ones.

 

[TheJay]

Has anyone else managed this and got any advice?

 

[Nigel Goodwin]

Has anyone else managed this and got any advice?

Managed what?, finding a plug? - as I've already mentioned, you can simply cut the ferrite bead off, it doesn't do anything - and only some PSU's even include them.

 

[Les Jones]

Your first step is to find a supplier of the plug. You will also have to specify the pin dameter. (The pin on the socket on the computer or the diameter of the hole in the plug.) I asume that 7.4mm is the outer diameter of the metal part of the plug. You could also try Googling "coaxial power connector make and model of your computer"

Les.

 

[TheJay]

Yep, it's 7.4mm x 5.0mm. I did a search earlier and I'm not seeing much.

 

[rjenkinsgb]

Have a look on ebay and amazon for places selling tip sets for universal adapters - you can usually find a matching one with a bit of searching.

The ones with two pins on the back can easily have wires soldered on plus heatshrink sleeve for strength, I've repaired quite a few laptop PSUs like that.

ps. If your plug has a centre pin rather than the pin side being in the laptop, the size is based on the outer diameter and the pin diameter, not just the inside of the plug sleeve.

Example:

Universal Tips Heads Adapter AC DC Power Supply Charger Multi Laptop Notebook | eBay

Find many great new & used options and get the best deals for Universal Tips Heads Adapter AC DC Power Supply Charger Multi Laptop Notebook at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

Yours may match this one from the Type C set?
"Black mouth with needle 7.4*5.0*0.6MM"

 

[TheJay]

Thanks, the pin is in the centre of the DC cable rather than the laptop. It does look like the one you quoted from Type C set is correct. I don't suppose you have any photos of this repair?

 

[rjenkinsgb]

I don't suppose you have any photos of this repair?

No, sorry.
The wires are soldered to the individual pins, with short pieces of small heatshrink, a slightly larger piece 2 - 3" long (previously) threaded on the cable slid back to those and shrunk, then finally a bit of large adhesive lined heatshink over the entire joint area, with it starting over the back of the connector body to prevent any flexing around the soldered pins.

That gives a very solid joint with a strain relief "tail".

 

[Nigel Goodwin]

No, sorry.
The wires are soldered to the individual pins, with short pieces of small heatshrink, a slightly larger piece 2 - 3" long (previously) threaded on the cable slid back to those and shrunk, then finally a bit of large adhesive lined heatshink over the entire joint area, with it starting over the back of the connector body to prevent any flexing around the soldered pins.

That gives a very solid joint with a strain relief "tail".

I used to do the same - mainly because I had lot's of those 'universal tips' at work - we used to sell Universal PSU's in the shop at work, and I often used to use them as replacements on repairs that came in. For the replacement PSU I'd fit the correct tip (the right way round ) and then apply heat shrink over the join, so they couldn't pull apart.

Then, rather than bin all the other tips, I'd chuck them in a small box sat in the window sill - so I had a goodly collection

If I then needed a DC plug for anything, just like you I'd solder wires to the pins, with thin heat shrink on each wire, then thicker heat shrink over the entire assembly. I used a lot for connecting power to CCTV cameras