Toshiba Satellite Pro M15-S405 PCB flux rot

[Jeff Liebermann]

Here's one I haven't seen before:
<http://802.11junk.com/jeffl/crud/toshiba-rot-02.jpg>
It's the motherboard from a Toshiba Satellite Pro M15-S405 laptop. The
brown crud is probably flux left over from the soldering operation or
something corrosive, that was trapped between the PCB and a thin
plastic "protective" covering under the DVD drive. The board acts
totally dead. No power, no charge lite, no sounds, no nothing. At
first, I thought that someone had spilled some liquid into the laptop.
Nope, because all the corrosion is BETWEEN the PCB and the plastic,
with nothing on top of the plastic. The plastic covering was totally
clean. There's no corrosion in the area that's NOT under the
"protective" covering, so it seems whatever did the damage, was
volatile.

The customer has 3 other identical laptops. I just inspected them
(through the DVD slot), and found no corrosion.

I'm not sure I'll be able to fix this one as the rotted traces in this
area are very tiny. It's probably not worth the effort for a 9 year
old laptop.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[Jeff Liebermann]

On Fri, 22 Apr 2011 16:46:23 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

Here's one I haven't seen before:
http://802.11junk.com/jeffl/crud/toshiba-rot-02.jpg

One more photo:
<http://802.11junk.com/jeffl/crud/toshiba-rot-03.jpg>

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[Jeff Liebermann]

On Fri, 22 Apr 2011 21:09:14 -0700 (PDT), spamtrap1888
<spamtrap1888@gmail.com> wrote:

On Apr 22, 4:46 pm, Jeff Liebermann <je...@cruzio.com> wrote:

 At
first, I thought that someone had spilled some liquid into the laptop.
Nope, because all the corrosion is BETWEEN the PCB and the plastic,
with nothing on top of the plastic.  The plastic covering was totally
clean.

Liquid might have landed on the PCB but then wicked between the
plastic sheet and the PCB, where surface tension held it in place.

Nope. Look at the photos. Most of the rot is in isolated patches
with no fluid connections to the edge. Also, the "protective" plastic
sheet has some kind of glue smeared on one side, covering the entire
area. It will take considerable effort to remove it. I don't think
anything can creep underneath (including capillary action).

 There's no corrosion in the area that's NOT under the
"protective" covering, so it seems whatever did the damage, was
volatile.

The surface area of any trapped liquid is relatively tiny.

True. It also took years for the stuff to finally eat away the
copper. Mostly, it ate the areas around the PCB vias (holes), which
again points to something during manufacture. Probably a tiny amount.
Were it not for the "protective" plastic trapping the stuff, it would
have probably evaporated away.

The customer has 3 other identical laptops.  I just inspected them
(through the DVD slot), and found no corrosion.  

I'm not sure I'll be able to fix this one as the rotted traces in this
area are very tiny.  It's probably not worth the effort for a 9 year
old laptop.

The corrosion is not bridging the traces? Is the corrosion conductive?

I can't tell yet. It's definately eating away the traces because the
failure is lack of on/off and lack of charging (so far). Bridging
would cause other problems. Incidentally, I checked all the fuses and
power buses. They're fine.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[spamtrap1888]

On Apr 22, 4:46 pm, Jeff Liebermann <je...@cruzio.com> wrote:

 At
first, I thought that someone had spilled some liquid into the laptop.
Nope, because all the corrosion is BETWEEN the PCB and the plastic,
with nothing on top of the plastic.  The plastic covering was totally
clean.

Liquid might have landed on the PCB but then wicked between the
plastic sheet and the PCB, where surface tension held it in place.

 There's no corrosion in the area that's NOT under the
"protective" covering, so it seems whatever did the damage, was
volatile.

The surface area of any trapped liquid is relatively tiny.

The customer has 3 other identical laptops.  I just inspected them
(through the DVD slot), and found no corrosion.  

I'm not sure I'll be able to fix this one as the rotted traces in this
area are very tiny.  It's probably not worth the effort for a 9 year
old laptop.

The corrosion is not bridging the traces? Is the corrosion conductive?

 

[Uffe Bćrentsen]

"Jeff Liebermann" <jeffl@cruzio.com> skrev i en meddelelse
news:ia34r69f6ol7inagablvvbgc315bivc7ii@4ax.com...

Here's one I haven't seen before:
http://802.11junk.com/jeffl/crud/toshiba-rot-02.jpg
It's the motherboard from a Toshiba Satellite Pro M15-S405 laptop. The
brown crud is probably flux left over from the soldering operation or
something corrosive, that was trapped between the PCB and a thin
plastic "protective" covering under the DVD drive. The board acts
totally dead. No power, no charge lite, no sounds, no nothing. At
first, I thought that someone had spilled some liquid into the laptop.
Nope, because all the corrosion is BETWEEN the PCB and the plastic,
with nothing on top of the plastic. The plastic covering was totally
clean. There's no corrosion in the area that's NOT under the
"protective" covering, so it seems whatever did the damage, was
volatile.

The customer has 3 other identical laptops. I just inspected them
(through the DVD slot), and found no corrosion.

I'm not sure I'll be able to fix this one as the rotted traces in this
area are very tiny. It's probably not worth the effort for a 9 year
old laptop.

From what I can see the PCB is flipped over (upside down).
Liquid (cola?) might have landed on the top surface and then it is wicked
through the PCB through the via's to the bottom side where it gets trapped
in between the PCB and the plastic covering.
Have seen almost the same with a Logitech keyboard.
The liquid that landed on the top surface was free to evaporate.
The liquid on the bottom surface was trapped and could etch away :-(



--
Uffe Bćrentsen

 

[Jeff Liebermann]

On Sat, 23 Apr 2011 11:43:48 +0200, "Uffe Bćrentsen"
<leiti_NOSPAM_@hotmail.com> wrote:

http://802.11junk.com/jeffl/crud/toshiba-rot-02.jpg

From what I can see the PCB is flipped over (upside down).

Correct. It's a bottom view.

Liquid (cola?) might have landed on the top surface and then it is wicked
through the PCB through the via's to the bottom side where it gets trapped
in between the PCB and the plastic covering.

Maybe. There's another sheet of plastic on the other side with holes
for connectors and mounting studs. I didn't see anything odd looking
through the plastic, but I didn't peel it off yet. When I get back to
the office on Monday, I'll take a closer look after I peel off all the
plastic.

Have seen almost the same with a Logitech keyboard.
The liquid that landed on the top surface was free to evaporate.
The liquid on the bottom surface was trapped and could etch away :-(

Good point, if it happened that way. I'll double check.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558