TECH: Firepower about to do some board work

[Lido]

I'm about to replace the 40 pin header and some molex headers on the
driver and MPU boards (next is the power supply). Before I start, I'm
wondering if the 40 pin has already been replaced. Also, there's a
charred looking area behind some fat blue resistors(?). Before I dig
into this, just want to make sure it's not unnecessary or a waste of
time if the charring is a bigger problem that I need to fix. See pics here:

<a href="http://x87x.com/ebay/IMG_4777.jpg" target=new><img
src="http://x87x.com/ebay/IMG_4777.jpg" width=50% height=50% border=0
title="click to enlarge"></a><br clear=all>
<a href="http://x87x.com/ebay/IMG_4778.jpg" target=new><img
src="http://x87x.com/ebay/IMG_4778.jpg" width=50% height=50% border=0
title="click to enlarge"></a><br clear=all>
<a href="http://x87x.com/ebay/IMG_4779.jpg" target=new><img
src="http://x87x.com/ebay/IMG_4779.jpg" width=50% height=50% border=0
title="click to enlarge"></a><br clear=all>
<a href="http://x87x.com/ebay/IMG_4780.jpg" target=new><img
src="http://x87x.com/ebay/IMG_4780.jpg" width=50% height=50% border=0
title="click to enlarge"></a><br clear=all>

Thanks.

[Hans]

Looks like the 40-pin has been re-soldered at some point, but likely
not replaced. Is it still 5 sections of 8 pins (original)? Or is it
4 sections of 10 pins (replaced)?

The burned boards are nothing unusual, in fact they all do that to
some extent. Those resistors have been replaced, again not
uncommon.... though I have seen better jobs of it. I've also seen
MUCH worse too.

Nothing of any significant concern though, all easy enough to repair
as long as you take your time and are careful.

-Hans

[Chris Hibler]

Those solder joints on the 40-pin connector look typical for when
solder is "reflowed" on this vintage board. The joint doesn't "wick"
the solder, and instead forms in a "donut" around the lead. If you
aren't going to replace the component, it's always best to remove the
older solder before flowing new solder in.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

[Lido]

Thanks. It is still 5 sections of 8 pins, so I guess I will replace. I
bought the male and female sides of the connectors, but I think someone
here recommended that the female ones are more important to replace.

[Andy_B]

On Feb 12, 9:10 am, Lido <sweepingoar@|nospam|yahoo.com> wrote:
> On 2/11/12 5:29 PM, Hans wrote:
>
> > Looks like the 40-pin has been re-soldered at some point, but likely
> > not replaced.  Is it still 5 sections of 8 pins (original)?  Or is it
> > 4 sections of 10 pins (replaced)?
>
> > The burned boards are nothing unusual,  in fact they all do that to
> > some extent.  Those resistors have been replaced, again not
> > uncommon.... though I have seen better jobs of it.  I've also seen
> > MUCH worse too.
>
> > Nothing of any significant concern though, all easy enough to repair
> > as long as you take your time and are careful.
>
> > -Hans

You might want to check the value of the two replaced resistors on the
left of the pic. The bands seem to be different colours to the rest
unless it is just discolouration from them getting a bit warm.

Andy

[Gott Lieb?]

5 sections of 8 pins does not necessarily mean they haven't been
replaced yet. Mouser and Digikey, and I'm sure other vendors, stock new
8 pin (09-52-3082) female connectors.

Posting a pic of the front side of the boards will be more of a
determining factor whether or not they've been replaced or not.

Jim

--
Gott Lieb?
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