Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Power adapter outing 12v instead of 19?

Status
Not open for further replies.

D_Zirt

New Member
Hi, I'm hoping some here can help me with my laptop power adapter. It's supposed to be putting out 19v to power my lappy, but the other day it just wouldn't work. So I checked it with my volt meter an it gave me a rating of 12v :confused: So is there something that could have burnt out that would make it drop that 7v? I really hope someone can help me, I dont really feel like shelling out $100 to replace it. Thanks
 
I assume that you have measured the voltage with no load, i.e. with the laptop disconnected.

If so, it is certainly dead.

Laptop power supplies are difficult and dangerous to fix. It may be possible to save a few dollars by buying a generic supply and fitting the cord from your broken one.

However, many manufacturers (including Dell) have special identifying chips in the power supplies, so you can't just supply the correct voltage.

This is real pain if it is combined with a badly designed connector, like Dell use.
 
Yes, you are right, it was measured with no load. Thanks for the quick reply, though it is sad news. It was a Toshiba btw
 
Diver300 said:
However, many manufacturers (including Dell) have special identifying chips in the power supplies, so you can't just supply the correct voltage.
I have never heard of this.
 
I²R said:
I have never heard of this.

I have heard of something very similar a few years ago. Toner or ink cartridges in some brands of printers contained an identification IC, making it impossible for non-OEM cartridges to be used.
 
Some Dell power supplies are connected with a three-core cable. Two cores provide the power and one connects to an identifying chip. I think it is a Maxim 1-wire device.

The laptop will not charge the battery unless it recognises the chip. This happens quite often because of the lousy connectors. I get a warning on screen that I should connect the correct power supply.

That only happens if there is power to the power supply, so the laptop certainly can recognise power and the correct power supply separately.
 
Simply don't buy a Dell laptop.

Choose a laptop with a standard DC connector.
 
Status
Not open for further replies.

New Articles From Microcontroller Tips

Back
Top