Defender Restoration

[SirPeale]

What little progress I've done, I've logged in brief here:

http://www.pealefamily.net/tech/newmame/index.php?cat=13

[SirPeale]

Replaced the 4116 RAM with 4164 and made an adapter.  Up and running again!

[SirPeale]

I'd forgotten that I bought a couple sound boards off eBay.  Went to test them today.

One a Joust (I think) and one another Defender.

Since the ROM was already in the Defender one, figured I'd just plug that one in.  Something weird...an extra pin on the power input.  I *think* it was pin 7 (which according to a Robotron drawing set, is unused) but I left it behind at the storage area (in hindsight, a dumb move).  On the original board that pin is missing.  Not knowing if it was a bad thing to chop it off, I left it alone.  The board numbers are the same.

Next, the one with the (I think) Joust ROM.  It wired up okay.  Fired up the game, immediately starts making noise.  Continues into the attract sequence.  Finally stops.

I play a game.  Weird having Defender making Joust sounds.  But they're amazingly appropriate. 

Next I pull the ROM from my original board and install it...nothing.  Not even in test.  Okay...

Pull the other Defender ROM and install it...also nothing!  Replace the Joust ROM...sounds again.   Okay.  I think I know what's going on.  I see zero ohm resistors on the sound board.  From my reading about the ROM board you have to change the "strapping" to get it to see the correct type of ROM.  It can take either 2732 or 2532, you just have to change the position of the resistors (essentially jumpers).  I'm betting it is similar, but haven't looked it up yet.

[SirPeale]

Pulled that "extra" pin out of that one SB.  Works great.  Still have no clue why it was there.

One theory is that someone replaced the connector at some point in the past, but didn't remove that pin.  But the solder looks factory.  Whatever.  Sound works 100% now.

[cw]

 

[SirPeale]

Now I just have to work on the rest of the beastie.  I took off the CP the other day to clean it up.  There was a Willis CPO on there.  I didn't realize at the time that the original was under it.  Nice!

...or not.  Horribly, horribly burned from cigarettes.  I had a replacement that someone gave me when they replaced theirs.  Like 5000% better than the one that was on there. 

I thought just *maybe* I could remove the old one and practice fixing it.  Nope...cracked in three pieces when I took it off.  Just as well...it was in *really* bad shape.

Not thrilled with the joystick either.  There is a *lot* of slop.  I know there are rebuild kits available, but they're quite expensive.  It's in decent shape otherwise.  Pinball machines have this nylon insert that goes around shafts and holds it within a hole...I wonder if I can find one in the right size. 

[ChadTower]

If a flipper bushing won't work I bet you could find something at a good plumbing supply store that will do the job.  That's an almost limitless supply of fittings and sizes - a lot of them in brass that won't wear the same as plastic.

[SirPeale]

Flipper bushing? Not what I'm looking for.

What I'm looking for is a nylon washer thing.  The edges are rolled to snap into the hole, and there is a "break" in it to allow it to compress so it fits in the hole.  I think I've heard them referred to as "nyliners" or something.

Edit: yep,that's what they're called.  Now if I could find one in the size I need...

http://www.marcospecialties.com/itemdesc.asp?ic=20-8790

[ChadTower]

Oooh, that part.  It's possible you could get that one and trim it down some... that's why it is an open loop, I think.  For different shaft diameters.

[RetroACTIVE]

I gave it some thought to use a set or pan head screw or something equivalent.  You could re bore the worn holes of the assembly to the size of the screw head  (My old worn 2 ways assemblies no longer had nice round holes... they were worn oblong).  Grind off the old worn pivot stumps on the cross member that the stick goes into... Then... tap a thread through the cross member and put a screw in on each side (essentially creating new pivot points).

Kind of winded... hope it makes the point.