Power adapter outing 12v instead of 19? - Electronic Circuits Projects Diagrams Free

D_Zirt · 3rd March 2008, 06:49 PM

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

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

Diver300 · 3rd March 2008, 07:06 PM

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.

D_Zirt · 3rd March 2008, 07:35 PM

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

I²R · 3rd March 2008, 10:43 PM

Quote:

Originally Posted by Diver300

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.

D_Zirt · 3rd March 2008, 11:15 PM

Come to think of it I²R, neither have I lol

Bob Scott · 4th March 2008, 03:46 AM

Quote:

Originally Posted by I²R

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.

Diver300 · 4th March 2008, 12:02 PM

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.

Hero999 · 4th March 2008, 12:55 PM

Simply don't buy a Dell laptop.

Choose a laptop with a standard DC connector.

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3rd March 2008, 06:49 PM	(permalink)
D_Zirt	Power adapter outing 12v instead of 19? 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 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

3rd March 2008, 07:06 PM	(permalink)
Diver300	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.

3rd March 2008, 07:35 PM	(permalink)
D_Zirt	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

3rd March 2008, 11:15 PM	(permalink)
D_Zirt	Come to think of it I²R, neither have I lol

4th March 2008, 12:02 PM	(permalink)
Diver300	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.

4th March 2008, 12:55 PM	(permalink)
Hero999	Simply don't buy a Dell laptop. Choose a laptop with a standard DC connector. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez