Building Regular ATX PC into Dell Dimension 8200 Case?

[Paul]

In other words, if a component needs to be soldered to a trace on the
middle layer of a mobo, how do you get the solder down in there and
not everywhere else too? Is it hard?

Commodity motherboards are four layer. Some were six layer, to solve routing
problems with certain large chips, or to add additional grounds to make
stripline or microstrip for things like RAMBUS routing. You might occasionally
find an eight layer motherboard, perhaps a server or something. But four
layers is a safer bet most of the time. Each pair of layers added, adds
10% to the blank motherboard PCB cost. (Four layer = X, six layer = 1.1*X,
eight layer = 1.1*1.1*X). PCBs with an amazing number of layers have been
fabricated, and if a PCB is complex enough and big enough, it can cost
on the order of $1500.00 to make just one.

There are limits to how thick a motherboard could be, and that may
constrain the layer count and prevent large numbers of layers. I
don't know how feasible it would be to make an 8 layer board, and
stay at say 62.5 thick or whatever.

Layers are joined by "vias". A via is a plated hole, running from top
to bottom of motherboard. If no tracks on the surface need to be
connected, all you see on the surface is a "donut" circle. Vias are
used to change layers, for the routing of the track.

Now, certain kinds of printed circuit boards, use "blind" or "buried" vias.
Since the PCB is a lamination of individual sheets of material, it's possible
to drill holes before joining everything together. If a high tech PCB uses
such a technique, it limits access to internal signals not poking through
to the surface. To break a connection in such a situation, may require
an X-Y positioner table and a drill press. You would not expect to find
buried via technology on motherboards. All the vias and holes on a motherboard,
should go from top to bottom, touching all layers.

When soldering capacitors, those will use a nice hole going all the way from
top to bottom. You should be careful not to drill into the hole (to "clean it"),
since that can damage the plating in the hole, and spoil continuity to
things connected internally to that plated hole. If you apply enough
soldering heat, you can pull copper lands off the PCB surface, so
toasting the board is a concern when doing repairs. Due to the usage
of "interference fit" between capacitor leg and motherboard, re-capping
a motherboard is harder than it needs to be. At my old employer, they
used "oversized" capacitor holes, which were easy as pie to work on.
By comparison, the motherboards where the capacitor legs barely fit in
the holes, those are a bitch to get out. Even if you snip off the
capacitor and just work on the legs, you can still have trouble
pulling out the leg. And if you're a butter fingers, you can
even pull the entire thru-hole right out of the PCB (I've done that).
If the material is properly heated, there shouldn't be much mechanical
resistance. It's when you didn't get it hot enough, that you apply
excessive force, and damage results.

Even with a vacuum de-soldering station, with regulated tip temperature
turned all the way up, I still have problems with electrolytic caps.

Paul

 

[reeltoreelguy]

Neighbor's about to trash a Dell Dimension 8200.

The thing's older than dirt, but seems like a nice case - albeit
probably infamously Dell-proprietary.

Aside from being a decent size and easy to pick up, the thing
also has an XP Home license sticker with product key on it.

Occurs to me that, if I need to build a PC for somebody in the
future, this case might save me 30-40 bucks.... and I'm a diehard
XP fan so....

So.... How incompatible is it? Anybody built up another mobo in
one?

As I remember that model uses DELL's infamous CLAMSHELL case as did many models. ALL DELL's from 1996 to 2000 or so are PROPRIETARY. Meaning they are NON STANDARD variations of the ATX standard, That means that the PSU pinouts are different, the mobos pinouts are a match to the PSU, some PSUs are 24pin plus 16 pin, others 24 plus 4. The cases all are just as weird. Although it IS possible to mix and match mobos and cases, both ATX and weird, It takes a lot of work as the mobos mountings are weird, the back plane is positioned differently, the PSU will need to be moved, 24 pin male/female point to point extensions need to be used to reach the mobo, the rear of the case will need to be modified as well as inside. Only thing that stays is thedrive cages. Unless you have a large spare parts pile and are good with tools and are a die hard DELL fan like me such a project is really not worth the effort in time and aggravation. My advice is a new used computer. Happymodding.

 

[Good Guy]

As I remember that model uses DELL's infamous CLAMSHELL case as did
many models. ALL DELL's from 1996 to 2000 or so are PROPRIETARY.
Meaning they are NON STANDARD variations of the ATX standard, That
means that the PSU pinouts are different, the mobos pinouts are a
match to the PSU, some PSUs are 24 pin plus 16 pin, others 24 plus 4.
The cases all are just as weird. Although it IS possible to mix and
match mobos and cases, both ATX and weird, It takes a lot of work as
the mobos mountings are weird, the back plane is positioned
differently, the PSU will need to be moved, 24 pin male/female point
to point extensions need to be used to reach the mobo, the rear of
the case will need to be modified as well as inside. Only thing that
stays is the drive cages. Unless you have a large spare parts pile
and are good with tools and are a die hard DELL fan like me such a
project is really not worth the effort in time and aggravation. My
advice is a new used computer. Happy modding.

You really took time to research into this! Were you researching into
this all this time? Peter wanted help in 2011 and you posted a solution
in 2014. You are really a dedicated guy to spend all that time finding
the correct solution. Congratulation and keep it up.

How is New Haven, Connecticut? "Optimum Online" must be very proud of you.