> Hi all,
> Well, it looks like I've finally destroyed the Ace...
Ow!
Your problems were probably caused by aggressive engineering cost
reduction. "Quality" boards are made of fiberglass and resin, have
plated vias and a solder mask. Many low-end products are missing
one or more of those features (mind you, a $100 TV set counts as low
end in terms of board quality).
If you were using a temperature controlled iron, one way to minimize
thermal damage is to have the iron barely above the melting point
of your solder. If your iron is a fixed temp, you can select a
lighter element (fewer watts to pump into the board). Practice
can also help. I remember obliterating boards as a kid. My Quest
Elf has a number of scorch marks and blobby solder joints. I keep
thinking about scanning it for an example, then cleaning it off and
repopulating it with decent sockets. If I ever finish the external
front panel and the computer doesn't come right up, that's probably
what I'll do - deconstruct and reconstruct with better parts.
Since you are past that point, if you can't smooth things out by
hand, they do make replacement eyes and lands and traces, but
they aren't cheap. Another Ace might be cheaper.
> I've just bid on some 2532 EPROMs on eBay from someone in Austria.
If you don't win the bid, I can probably help you with a couple of
2532s. If you get me the contents as a binary or Intel Hex file, I
can program them first.
B.G. Micro has 2532s for $2.00 each or 10 for $17.50.
> Does anyone know how I could rescue this machine? It looks like the
> RAMs are definetly fried, along with some of the logic as well...
If it were mine and I didn't have a logic probe or oscilloscope and
had to resort to "shotgunning" RAMs, I'd at least put machined-pin
sockets in every place I pulled a chip from. It's not an awesome price,
it's kindof OK, but B.G. Micro has a variety of sized (14-pin to 40-pin
for 3/$1.00). At least then, you won't be lifting any _more_ pads. If
visual access is an issue (i.e., you want to see under the socket to
ensure there isn't any hidden damage), you can install machined pin strips
or break individual pins from the sockets and solder them in without a
plastic frame. It's harder to insert an IC, but you can see the board.
> Has anyone here either repaired one of these machines or got a spare
> Ace to sell me?
Sorry. Never seen an Ace, just the ZX-80 and ZX-81. From all the
discussion, I'm getting a good picture in my head (and I even toyed
with the idea of building one from scratch), but for now, I have to
focus on getting my SBC6120 built.
Cheers,
-ethan
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Received on Tue Dec 10 2002 - 15:18:00 GMT