Near Hopeless Laptop Repair

MEXICOWANDERER wrote:
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!

One thing I have learned over the years as an electronic tech is to NEVER "assume" anything..

There is no hard and fast rule as to how a low voltage plug is wired, it could be pos inside or it could be pos outside. Generally it will be pos on the inside BUT one should always verify the actual polarity before engaging a potential display of smoke.

I know this is not the answer you were looking for BUT I would recommend SKIPPING this power brick you have and BUYING a new UNIVERSAL laptop power brick.

The Universal Laptop bricks come with a multitude of specially made adapters, one should fit your laptop. Secondly, the some Universal laptop bricks will also CORRECTLY MATCH THE VOLTAGE for the adapter selected and others have a manual switch. Just pick the correct adapter, set the voltage and you are done..

The 19.5V at 2.8A is a 56W brick so you can use any 60W or greater universal laptop power supply..

HERE is a 70W with adapter tips for $13.. as an example..