Laptop Lead Repair?

[TheJay]

This is interesting, I think that the PSU element is glued though, so I don't think it would be feasible to replace the entire length like this?

https://www.aliexpress.com/item/1005002048726615.html

 

[Nigel Goodwin]

This is interesting, I think that the PSU element is glued though, so I don't think it would be feasible to replace the entire length like this?

https://www.aliexpress.com/item/1005002048726615.html

What do you mean by 'element'? - whatever you mean, it's the wrong term in English.

If you mean the PSU itself, then they are glued together, but are easily cut apart (hacksaw or Dremel) and then glued back together.

 

[TheJay]

That's what I mean, I didn't want to make a mess cutting it open. Surely that's going to look messy? Also, what kind of glue to you use to stick it back together? It would need to be very resistant to heat.

 

[Tony Stewart]

You may have noticed these cables ONLY have 3 wires. V+, V- and Remote sense to regulate the out voltage due to losses in the cable. The better ones use 4 wires.

I might challenge my surgical skills to repair the broken cable connector and reinforce with polyurethane for strain-relief. But it is not easy to just cut and remove all the jacket material to splice and heatshrink the wires. So replacing the entire cable may be easier. Any questions?

The case seal is tack glued and may be cracked open. But you should expect lots of shields and stuff that must be glued back together. A chinese repair shop might be your best bet or replace with a universal charger.

https://www.amazon.ca/Powseed-Unive...ompatible/dp/B0711MP9ZX/ref=asc_df_B0711MP9ZX or get one with your AC plug.

 

[Nigel Goodwin]

That's what I mean, I didn't want to make a mess cutting it open. Surely that's going to look messy? Also, what kind of glue to you use to stick it back together? It would need to be very resistant to heat.

That's why you cut it, rather than crow-baring it, which often breaks the casing - just carefully saw round the join where it's glued, then afterwards just glue it back together with epoxy resin - wrap insulation tape round it to hold in place while the epoxy cures.

 

[TheJay]

Thanks for your replies.

I discovered it's possible to non-destructively open the case of laptop PSUs. Aside from a 1mm piece of plastic inside, there is no other damage to the plastic.

This is an OEM charger, yet it only has three pins. So, whether or not four is better, this tells me I need three wires.

Time to get ordering.

 

[TheJay]

Okay, so it might take two months to arrive but it was £2.74.

https://www.aliexpress.com/item/32683885147.html?spm=a2g0o.order_list.order_list_main.5.21ef1802ZMbmr7

 

[Nigel Goodwin]

Okay, so it might take two months to arrive but it was £2.74.

https://www.aliexpress.com/item/32683885147.html?spm=a2g0o.order_list.order_list_main.5.21ef1802ZMbmr7

I order a LOT from Aliexpress, they are fairly decent on speed these days - 2 to 3 weeks is probably all.

 

[TheJay]

Sounds good to me!

Out of interest, how come the solder on the three wires where they go through the circuit board is dome shaped? It's not like that elsewhere. I've never seen solder like that before, do I need to replicate and if so, how is that done?

 

[Nigel Goodwin]

Sounds good to me!

Out of interest, how come the solder on the three wires where they go through the circuit board is dome shaped? It's not like that elsewhere. I've never seen solder like that before, do I need to replicate and if so, how is that done?

No, you don't need to try and duplicate it - it's simply had too much solder applied.

The rest of the board will have been flow soldered, but the external wires are added by hand - and whoever did it isn't very good at soldering.

 

[JimB]

how come the solder on the three wires where they go through the circuit board is dome shaped?

It looks as though there is some kind of ferrule crimped on to the end of the wires, and whoever soldered the wire/ferrule onto the board used a BIG BLOB of solder.

It's not like that elsewhere. I've never seen solder like that before,

Good.

do I need to replicate

No, big blobs like that are considered to be bad technique and would fail any critical QA inspection.

Ideally you should be able to see the outline of the wire to ensure that the solder has "wetted" the wire surface and made a good joint.
Anything could be happening under that blob. Yuk.

JimB

 

[TheJay]

Thanks both, that's really good to know. Let's see what happens.

 

[Nigel Goodwin]

No, big blobs like that are considered to be bad technique and would fail any critical QA inspection.

Not in China!

 

[JimB]

Not in China!

Where the soldering QA mantra is often:

" The bigger the blob, the better the job"

JimB

 

[Nigel Goodwin]

Where the soldering QA mantra is often:

" The bigger the blob, the better the job"

JimB

Is it soldering you're talking about?

 

[TheJay]

Oh, that sounds naughty!