Date:         Sun, 8 Jul 2012 11:32:00 -0700
Reply-To:     neil n <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil n <musomuso@GMAIL.COM>
Subject:      Re: Digifant ECU: Corrosion? And.... Rosin or Heat Damage? PICS
Comments: To: David Beierl <dbeierl@attglobal.net>
In-Reply-To:  <4ff98ba4.027dcd0a.7434.44a1@mx.google.com>
Content-Type: text/plain; charset=ISO-8859-1

On Sun, Jul 8, 2012 at 6:30 AM, David Beierl <dbeierl@attglobal.net> wrote:

> At 09:03 PM 7/6/2012, neil n wrote:
>>
>> On LH end of the PCB, there appears to be some kind of corrosion.
>> Almost looks like rust. That edge of the PCB is a different colour
>> than other edges:
>
>
> Certainly looks as though some water got in there - what does the inside of
> the case look like?
>
>> Clean up with Isopropyl?
>
>
> I guess.


Thanks.

I recently got my new glasses.    ;^)

Didn't notice anything untoward on inside of case. Tried a little
Isopropyl. Did nothing.

Seems what I saw as corrosion may be the surface coating lifting away
(or ? process) allowing the copper trace to be seen. If that makes
sense.


>
>> And, I *think* this is simply rosin left over from factory soldering
>> job, but could they be signs of heat damage?
>
>
> Not from factory but from rework of some kind - replacement of driver or
> reflow of bad joint.


Interesting. There were quite a few of these spots.


>
>> ... There are white globs
>> covering what may be fasteners and white ribbon connectors between
>> them.
>
>
> Those are soldered connections -- apparently VW noticed that they are among
> the most prone to fatigue failure of the solder and hoped to help - I'm
> guessing that's an 022D ECU with some surface-mount components on the back
> of the big board and a substantial shield can over the small one.


I thought it might be a D suffix ECU but don't see that in the PN on ECU case.

I don't recall seeing components on backside of either board or a heat shield.

Thanks much,

Neil.


--
Neil n

65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp

'88 Slate Blue Westy to be named.

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG Gas I4/VR Swap Google Group:

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines