my friend VIC. :(

Well, there I was...
Driving down the road when beep/flash/beep/bee/fl.. blank.
There went the VIC. Then it came back. Then it went away.

So now it's sitting on my lab bench and I'm staring at a
mechanical failure of the solder joint that holds the main
voltage regulator diode on the board.

Heat cycle stress.

Now to see if I still remember how to do precision solder work.

Photos later.


--
DougW

DougW wrote:
> Well, there I was...
> Driving down the road when beep/flash/beep/bee/fl.. blank.
> There went the VIC. Then it came back. Then it went away.
>
> So now it's sitting on my lab bench and I'm staring at a
> mechanical failure of the solder joint that holds the main
> voltage regulator diode on the board.
>
> Heat cycle stress.
>
> Now to see if I still remember how to do precision solder work.
>
> Photos later.

http://revbeergoggles.com/temp/crack.jpg
http://revbeergoggles.com/temp/nocrack.jpg

Didn't quite get the focus on the second shot, but the first sure shows where the problem was.

--
DougW

DougW wrote:
> DougW wrote:
>> Well, there I was...
>> Driving down the road when beep/flash/beep/bee/fl.. blank.
>> There went the VIC. Then it came back. Then it went away.
>>
>> So now it's sitting on my lab bench and I'm staring at a
>> mechanical failure of the solder joint that holds the main
>> voltage regulator diode on the board.
>>
>> Heat cycle stress.
>>
>> Now to see if I still remember how to do precision solder work.
>>
>> Photos later.
>
> http://revbeergoggles.com/temp/crack.jpg
> http://revbeergoggles.com/temp/nocrack.jpg
>
> Didn't quite get the focus on the second shot, but the first sure
> shows where the problem was.

"BAH"

Well, that seemed to work till I got about ten miles down the road and *paff* it went out again. After I stopped and the Jeep
rested it came back, flickered a bit on the way home, then went out. Came back up about the time I got home.

!!!!I HATE TRANSIENT FAULTS!!!!
Give me a nice smoked component any day, a blow fuse,....

Going to have to rip it apart again and go through every connection the hard way. It could be that diode was heat stressed to the
point it's going into thermal failure, but usually they just let out the magic smoke.

The other option is to dump the VIC, which doesn't do more than provide a few idiot lights.

--
DougW

"DougW" > wrote in message
...
> DougW wrote:
>> DougW wrote:
>>> Well, there I was...
>>> Driving down the road when beep/flash/beep/bee/fl.. blank.
>>> There went the VIC. Then it came back. Then it went away.
>>>
>>> So now it's sitting on my lab bench and I'm staring at a
>>> mechanical failure of the solder joint that holds the main
>>> voltage regulator diode on the board.
>>>
>>> Heat cycle stress.
>>>
>>> Now to see if I still remember how to do precision solder work.
>>>
>>> Photos later.
>>
>> http://revbeergoggles.com/temp/crack.jpg
>> http://revbeergoggles.com/temp/nocrack.jpg
>>
>> Didn't quite get the focus on the second shot, but the first sure
>> shows where the problem was.
>
> "BAH"
>
> Well, that seemed to work till I got about ten miles down the road and
> *paff* it went out again. After I stopped and the Jeep rested it came
> back, flickered a bit on the way home, then went out. Came back up about
> the time I got home.
>
> !!!!I HATE TRANSIENT FAULTS!!!!
> Give me a nice smoked component any day, a blow fuse,....
>
> Going to have to rip it apart again and go through every connection the
> hard way. It could be that diode was heat stressed to the point it's
> going into thermal failure, but usually they just let out the magic smoke.
>
> The other option is to dump the VIC, which doesn't do more than provide a
> few idiot lights.
>
I don't know if this is still true, but a pretty smart guy once told me that
electronic components including printed circuit boards are designed to be
soldered once and only once. That's a pretty good looking repair but you
had to apply more heat to melt the existing solder than the assembly was
designed to take. This is his theory anyway.

Earle


** Posted from http://www.teranews.com **

Earle Horton wrote:

> I don't know if this is still true, but a pretty smart guy once told
> me that electronic components including printed circuit boards are
> designed to be soldered once and only once. That's a pretty good
> looking repair but you had to apply more heat to melt the existing
> solder than the assembly was designed to take. This is his theory
> anyway.

Fairly accurate theory. Rework is always possible but you have
to take care not only with how hot you get components but for how
long you keep them that way. I use an Ungar solder station
(adjustable temperature) and heat sinks to protect components.
Go in there with one of those cheap wallyworld solder guns and
you can easily fry things.

Tomorow I pull the VIC out again and take it apart. Right now I'm
betting the same thermal stress that caused that crack also caused
the diode to get overheated and I just reconnected an already nearly
dead part.

Anyhoo, I've got an email in with one of the dealers I use. Betting
it's a junkyard part or at least over $100.

--
DougW

DougW wrote:

"ouch!"

Expensive little doodad.
Dealership wants $1,040 for it!

Think it's just going to have to be twitchy
till I can either figure out what needs to
be replaced/resoldered or run across a junkyard
with a burnout/rollover I can pry one out of.

--
DougW

DougW wrote:
> DougW wrote:
>> Well, there I was...
>> Driving down the road when beep/flash/beep/bee/fl.. blank.
>> There went the VIC. Then it came back. Then it went away.
>>
>> So now it's sitting on my lab bench and I'm staring at a
>> mechanical failure of the solder joint that holds the main
>> voltage regulator diode on the board.
>>
>> Heat cycle stress.
>>
>> Now to see if I still remember how to do precision solder work.
>>
>> Photos later.
>
> http://revbeergoggles.com/temp/crack.jpg
> http://revbeergoggles.com/temp/nocrack.jpg
>
> Didn't quite get the focus on the second shot, but the first sure
> shows where the problem was.

And of course it failed. Why? Because I missed another problem
spot. This one was a slight discoloration in one of the via's and
an adjoining trace. Looks like an overheat melted part of a trace
and caused a break in the circuit. This may have happened because
I fixed the primary problem. I'm sorta hoping the two aren't related
as that would indicate something else. A busted part that without
detailed schematics I'm simply not going to be able to diagnose.

http://revbeergoggles.com/temp/doh1.jpg
http://revbeergoggles.com/temp/doh2.jpg
http://revbeergoggles.com/temp/doh-fixored.jpg

I'm not terribly proud of the repair work. The space was way
too tight to put down a replacement trace or to jumper, so I
just ran a wire with some insulation between the closest available
points on that trace. The wire actually goes through the board
and solders to the other side.

p.s. for those that don't do board work, a "via" is simply a jumper
between sides of the board. A hole with solder in it to connect
traces from the front to the back.


One other thing I've learned from this is my eyeballs aren't as
good as they once were. I used to be able to see teeny tiny things
but found myself using a combination of magnifying glass and the
digital zoom offered by the camera. :/

--
DougW
Getting old sucks, don't do it!

DougW wrote:
> DougW wrote:
>> DougW wrote:
>>> Well, there I was...
>>> Driving down the road when beep/flash/beep/bee/fl.. blank.
>>> There went the VIC. Then it came back. Then it went away.
>>>
>>> So now it's sitting on my lab bench and I'm staring at a
>>> mechanical failure of the solder joint that holds the main
>>> voltage regulator diode on the board.
>>>
>>> Heat cycle stress.
>>>
>>> Now to see if I still remember how to do precision solder work.
>>>
>>> Photos later.
>> http://revbeergoggles.com/temp/crack.jpg
>> http://revbeergoggles.com/temp/nocrack.jpg
>>
>> Didn't quite get the focus on the second shot, but the first sure
>> shows where the problem was.
>
> And of course it failed. Why? Because I missed another problem
> spot. This one was a slight discoloration in one of the via's and
> an adjoining trace. Looks like an overheat melted part of a trace
> and caused a break in the circuit. This may have happened because
> I fixed the primary problem. I'm sorta hoping the two aren't related
> as that would indicate something else. A busted part that without
> detailed schematics I'm simply not going to be able to diagnose.
>
> http://revbeergoggles.com/temp/doh1.jpg
> http://revbeergoggles.com/temp/doh2.jpg
> http://revbeergoggles.com/temp/doh-fixored.jpg
>
> I'm not terribly proud of the repair work. The space was way
> too tight to put down a replacement trace or to jumper, so I
> just ran a wire with some insulation between the closest available
> points on that trace. The wire actually goes through the board
> and solders to the other side.
>
> p.s. for those that don't do board work, a "via" is simply a jumper
> between sides of the board. A hole with solder in it to connect
> traces from the front to the back.
>
>
> One other thing I've learned from this is my eyeballs aren't as
> good as they once were. I used to be able to see teeny tiny things
> but found myself using a combination of magnifying glass and the
> digital zoom offered by the camera. :/
>

Any upstream issues? Usually when I see burned traces like that,
something like a pump or sensor has failed.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

Mike Romain wrote:

> Any upstream issues? Usually when I see burned traces like that,
> something like a pump or sensor has failed.

Nope, and that's what gets me with this doodad. The VIC only looks at
a few things. Coolant/washer fluid level, doors being open/closed,
transfer case position, and it has the service countdown and clock.
First thing I thought of was a bad power/ground/fuses, but every wire
and sensor checked out.

The VIC has a self-diagnostics and that passed even though it was
cutting out after a few minutes of driving. That made me think it
was power/ground. As it turned out, the first problem was mechanical,
I could make the VIC cut out by smacking it with my hand. That turned
out to be the diode (current regulator) that had a nice crack around
both solder connections. Not what I expected, usually it is the heavier
components that pull away.

On the plus side, the VIC was an "option" so simply disconnecting it
won't hurt anything. I could even move the AC controls down and install
a touch-screen GPS or TV.

On the ?bright? side I found a dealer that will sell a new one to
me for $842, better than the local one that wants $1,040 plus tax.

--
DougW

> http://revbeergoggles.com/temp/doh-fixored.jpg

That's a nice CMOS chip in the picture. A cheap soldering
iron can have as much as 40V on the tip due to AC leakage.

On sensitive stuff, I either ground the tip to the ground
prong on the outlet, or just unplug it when I actually
make contact with the board and plug it back in to keep
it hot afterwards. If you directly ground the tip, make
sure the item is unplugged and the caps are drained.

http://pdf1.alldatasheet.com/datashe...MC33060AP.html