For the second time in 12 months, i find myself in need of a replacement a laptop charger power lead.

The one I need starts with a three-pin mains plug and terminates in a cloverleaf plug which fits into the input side of the charger. I need a good quality one - I have gone through two cheapos in the last year.

The circuits just refuse to conduct after a while. I think what is happening is that the manufacturers are using low grade metal in the tongues of the 3-pin plugs. After a while, this seems to crystalize internally and fracture beneath the surface leading to a loss of conduction. However, the crack is not visible from the outside but only shows as an open circuit on a multimeter.This may also be related to the fact that my old laptop drawers a fair bit of power (6 Amps out).

Do MK, who used to have a good quality name, do anything like this ?

All I can see on the web at the moment is variously priced poor quality stuff - though the Lindy one does offer a 10 year guarentee.

Nick

Edited 23 March, 201115 yr by Clunkclick

When I need them, I buy these:

http://www.ebuyer.com/product/43147

I've ordered dozens, and not had a problem yet with the Belkin ones.

Crystalise the copper to stop it conducting... seriously!

More likely the copper plate has been pushed back so that the pins no longer contact, or there has been strain damage wouldn't you think?

Strain/wrap damage would certainly seem more likely to me....

And in the ones I see, it's more likely to be the transformer cable rather than the UK 3-pin section, as the transformer cable is usually thinner and more fragile.

Just to add I've never seen a faulty power lead, kettle style or laptop cloverleaf, without serious damage in more than 10 years working in IT.

Far more likely you have problems with the power brick. I'm on my second in 6 months.

+1 for the transformer.

My Toshiba one started acting up before it eventually died one evening when I really needed it for something important. I replaced it with a universal one from Argos for £50

Crystalise the copper to stop it conducting... seriously!

More likely the copper plate has been pushed back so that the pins no longer contact, or there has been strain damage wouldn't you think?

One of the pins later broke completely and revealed the spindly inner shaft buried in the lower plastic part of the pin, which looked like poor quality aluminium, definitely not copper.

Nick

Edited 25 March, 201115 yr by Clunkclick

Strain/wrap damage would certainly seem more likely to me....

And in the ones I see, it's more likely to be the transformer cable rather than the UK 3-pin section, as the transformer cable is usually thinner and more fragile.

Intuitively, that's what I initially thought. Multimeter testing says otherwise. I had exactly the same problem about a year ago and, on that occasion, it was the 3 pin plug to cloverleaf that had gone.

The charger/laptop is of 2003 vintage when the design quest was to raddle as much speed out of the processor as possible. And at that time that meant v.high power consumption. The Lite-On charger, which is unventilated, after an average charge, can get very warm.

Output rated at 20v 6 amps.

Nick

Edited 25 March, 201115 yr by Clunkclick

just to be sure, i've re-checked the charger primary and secondary circuits on the multimeter. Both show continuity, 1.77Meg Ohm on the primary and 1.00 Meg ohm on the secondary. Even the broken stump of the negative pin on the three Pin plug refuses to demonstrate continuity.

There is a possibility that the failure is mechanical rather than electrical, in that I may have sat on the three-pin plug and caused one of the pins to fracture - though I can't remember doing so - must have been a heavy night !

On strength of previous identical measurements i've ordered a replacement cable + 3pin. see what happens tomorrow when it arrives.

Postscript - Sat Evening.

All fixed and charged-up.

Nick

Edited 26 March, 201115 yr by Clunkclick