Forum Discussion

MEXICOWANDERER's avatar
Dec 29, 2015

Near Hopeless Laptop Repair

WAY WAY south of the border.
UPS, mail, computer parts a thing of dreams.

An OLD laptop works fine. Dead battery. Power supply 19.5 volt brick burned its circuit board. 2.8 amps @ 19.5 volts. Battery says 10.0 volts.

I have a spare 19.0 volt 3.8 amps power brick

But the laptop plug is larger on the bad brick laptop.

Zero continuity on the OUTER plug conductor. This plug is darned near the size of a RG6 coax fitting with no threads of course. It is merely big.

Question. No way to determine polarity orientation. Is the center wire connector ALWAYS the positive conductor? Meaning the outer ring is the negative connector?

The original umbilical is bad I assume at the plug. If I scalpel cut the plug strain relief am I going to find something I can heat and wick the solder off? Attach a replacement cable (the replacement brick) then run several layers of adhesive heat overtop?

The laptop is OLD. The nearest place to buy a 400 dollar replacement for 800 dollars is a 600-mile round trip.

The computer is used for a small business not for pleasure.

Any help or comments will be greatly appreciated. I am by no stretch of the wildest imaginatiin a "computer tech". Thanks In Advance!

14 Replies

  • I have never come across a laptop jack that was hot on the outside ring. My experience primarily with old Dell and IBM laptops.... I highly believe that you will have no problem just soldering the old plug onto the cord for the spare power supply ... hot to center, ground to ring.
  • I don't know any reason for not cutting off the cable and checking continuity and then splicing to the replacement brick. Sometimes the cable is really a coax cable and a little more care is needed in stripping off the outer cover. If the cable is good, I would save the plug and about 6" of wire, cutting the strain relief is a real pain. Soldering is soldering, my Basic Electronics, Professor explained that all points along the length of a cable are essentially the same. So it is no better to solder to the plug than the cable.
  • I would think the center wire is hot and the outside pin is ground.