[Noisebridge-discuss] fixing laptop power connectors

[travis+ml-noisebridge at subspacefield.org]

On Wed, Nov 03, 2010 at 09:22:01AM -0700, Jonathan Foote wrote:
> Is it a barrel connector plug?

I think so.

> I've fixed a lot of these. First consider making a microprobe with a
> pin and an alligator clip to check continuity on the small pins. On
> the PCB side, look carefully at the solder joints. Sometimes the
> solder will crack or solder + copper will pull away from the board.
> These can be nearly invisible, so  use the inspection scope. If you
> can see a problem,  "sweat" the solder joints to reflow them with the
> hot air station. Or maybe just sweat it anyway.

I've never done this kind of stuff... if anyone has time to show me
how this week or weekend, I'd really appreciate it.

I understand the basic principle, but don't know how to recognize
when solder has gone molten, what temp to use, how to operate the
equipment, etc.

> On the cable side. low-end injection molded plugs can be super flaky.
> Cut the cable and make sure you have continuity all the way from the
> PCB to the cable ends, and also check the PSU output. (You can splice
> it back up.) Rarely, but it can happen, a PSU will look like it's OK
> on the voltmeter but can't  deliver the current so it fails under
> load. Try testing with a load like a power resistor.

Hmm, interesting.

It is hard to hit the center conductor of the barrel plug with my
probes; something smaller may be needed, but it does register 19.1V
(nominal 19V).

> There may be mobo mojo that disallows operation with a weak or missing
> battery

Hmm, well, with the battery in it works fine, it just will drain the
battery and the linux /proc stuff for the A/C adapter says its
offline.  Almost 100% sure it's not a software issue, though, since I
booted Windows and from what I could tell, wasn't any better.

Thanks for the info.
-- 
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