[SFDXA] Laptop a/c power supply question

[Bill Dzurilla]

Anyone know something about laptop a/c power adapters? 


The 18.5v 3.5A N193 adapter on my Compaq 610 stopped working, and I wanted to replace it with another adapter I had with the same specs but a different connector plug to the computer.  When I cut the N193's cord from the p/s to the laptop, to my surprise there were 3 wires: white, black, and green.  The white  goes to the center hole on the plug (positive) and black goes to the outer barrel.  But I could not get any continuity between the green wire and any point on the plug, touched everything with the meter.  So I tried hooking up the other adapter with just the white to positive and black to negative and the green not connected.  This did not work, at least it did not energize the laptop.  So I assume the green wire must be connected somehow.  The plug is molded and can't be opened, at least not easily.

Any thoughts?

Thanks and 73,
Bill NZ5N