Build Your Own Arcade Controls Forum

Arcade Collecting => Pinball => Topic started by: SirPeale on January 27, 2010, 11:28:13 am

Title: Rebuilding a Gameplan MPU-1
Post by: SirPeale on January 27, 2010, 11:28:13 am
I'm in the process of repairing a "Foxy Lady" pinball that will be donated to the American Classic Arcade Museum when it's done.

This unit sat in a storage shed for ~20 years until it was "unearthed" recently.

Of course the MPU-1 board has the usual battery damage.

First thing I've done is soak the board in vinegar to neutralize the batter damage.  Then a good rinse and dried in the oven for several hours.

I'm trying to source the DIP switches now...these (http://www.mouser.com/ProductDetail/Omron-Electronics/A6T-8104/?qs=sGAEpiMZZMv%2f%252b2JhlA6ysKY5RvBMW9bi%252b4wsaGiozc0%3d) don't quite look what I'm going for here...

What's a better match on Mouser?
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on January 27, 2010, 11:49:45 am
I guess it helps if I get the correct mounting type (http://www.mouser.com/ProductDetail/CK-Components/BD08/?qs=sGAEpiMZZMv%2f%252b2JhlA6ysMM4cIGc%2fmHBleW5MkzBnX0%3d)...
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on January 28, 2010, 07:47:12 pm
Anyone?
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on January 29, 2010, 02:45:01 pm

Considering where this game is going to end up worst case is to just hard jump the config...
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on January 30, 2010, 03:37:46 pm
The whole board is bad.  Worst battery damage I've ever seen.  I'm fine with replacing the switches.

I found a bartop board that had a neat trick: socketing the switchbanks.  Switches go bad, just swap them out.  Might try that.
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on January 30, 2010, 04:19:00 pm

Almost all of my spare Berzerk ZPUs have broken switchbanks.  Probably rough handling.

You shouldn't have to socket them.  They rarely change anyway - just get it all cleaned up and put in some new ones.  They won't get hit with that style acid again once you relocate whatever caused that.
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on February 02, 2010, 05:03:39 pm
Sandblasted the board today.  Yes, it's an extreme measure.  Yes, it needed it.

Should have taken a "before" shot.  Didn't.

I've got my work cut out for me.   I was going to try and salvage the non-socketed chips, but they're too difficult to remove without damaging them.  So I'll replace them.

Anyone have a schematic handy?
Title: Re: Rebuilding an AS-2518-35
Post by: lilshawn on February 02, 2010, 05:11:45 pm
the foxy lady uses a mpu-1 system and they are basically the same..... this is for "chuck-a-luck" most schematics should match.

http://www.ipdb.org/files/3020/Gameplan_model_110_schematics.pdf (http://www.ipdb.org/files/3020/Gameplan_model_110_schematics.pdf)
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on February 02, 2010, 05:14:33 pm
the foxy lady uses a mpu-1 system and they are basically the same..... this is for "chuck-a-luck" most schematics should match.

http://www.ipdb.org/files/3020/Gameplan_model_110_schematics.pdf (http://www.ipdb.org/files/3020/Gameplan_model_110_schematics.pdf)

I was just looking at that, but that's not what I'm looking for.  I'm looking for the schematic for the AS-2518-35 that's in it. A couple of the chips I need to replace had the numbers removed when I blasted it, plus a few other parts.  Besides, its a good idea to have it.
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on February 02, 2010, 05:44:16 pm
Should have taken a "before" shot.  Didn't.

A couple of the chips I need to replace had the numbers removed when I blasted it, plus a few other parts. 


Double ouch!   :-\
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on February 02, 2010, 06:18:22 pm
I'm not worried.  It's well documented, I just need the schematic.  I see references to people having it on the 'net but so far haven't found it.  But I've also given it about two minutes of searching.
Title: Re: Rebuilding an AS-2518-35
Post by: lilshawn on February 03, 2010, 02:33:13 am
fine, http://arcadearchive.com/pinball/trek/Schematic-MPU%20Module%20AS-2518-35.pdf (http://arcadearchive.com/pinball/trek/Schematic-MPU%20Module%20AS-2518-35.pdf)  :whap



i'm going to bed now.
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on February 03, 2010, 04:24:06 pm
fine, http://arcadearchive.com/pinball/trek/Schematic-MPU%20Module%20AS-2518-35.pdf (http://arcadearchive.com/pinball/trek/Schematic-MPU%20Module%20AS-2518-35.pdf)  :whap



i'm going to bed now.

Muchas gracias!

I've removed two sockets.  Man those things are a pain.  I'm just glad they're in bad shape (as strange as that sounds) as it made the removal process a lot smoother.  Fixing the holes and whatnot should be fun...
Title: Re: Rebuilding an AS-2518-35
Post by: lilshawn on February 05, 2010, 01:26:12 am
i find on allot of those old boards, using a dremel with a cutoff wheel to chop the ic's legs off right next to the chip, then using needle nose pliers and the soldering iron to take the stumps out, makes things allot easier....and less likely to rip of a trace because a leg is still semi-attached to the board.

it's easier to do it one at a time than to try and get all 20 at once IMO
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on February 05, 2010, 10:21:16 am
The dremel throws little metal slivers around.  Be careful there.  It's also a LOT easier to bounce the thing and gouge another part.
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on February 05, 2010, 10:38:48 am

Actually, I was thinking more along the lines of throwing slivers around the PCB, not into your eye.

But eye injuries are no joke, true enough, I'm recovering from one right now.   :(
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on February 05, 2010, 11:57:55 am
i find on allot of those old boards, using a dremel with a cutoff wheel to chop the ic's legs off right next to the chip, then using needle nose pliers and the soldering iron to take the stumps out, makes things allot easier....and less likely to rip of a trace because a leg is still semi-attached to the board.

it's easier to do it one at a time than to try and get all 20 at once IMO

I always do this when removing ICs.  I was just trying to salvage the existing ones.
Title: Re: Rebuilding an AS-2518-35
Post by: ChadTower on February 05, 2010, 12:18:11 pm
Yeah, we heard you did it on a Burger King christmas card or something.


Nah, I scratched my cornea right before the AFC title game started.  Bad scratch, too.
Title: Re: Rebuilding an AS-2518-35
Post by: lilshawn on February 06, 2010, 10:56:29 am
Quote
The dremel throws little metal slivers around.  Be careful there.

it does? i usually use a mini cutoff disk (the non-fiberglass re enforced kind.) and get nothing but powder. which i just wash off with a spray of contact cleaner. no big chunks are involved at all.


Quote
It's also a LOT easier to bounce the thing and gouge another part.

that usually only happens because your speed is too slow, and your pressing too hard/too fast... causes the end to bind up instead of just cutting through the metal. I don't really need to talk about making sure you hang on to it good n' tight do i?

"let the tool do the work for you" is what my shop teacher used to say....untill he chopped off his fingers...then he became the computer studies teacher...which was okay since i took that too.

what where we talking about?
Title: Re: Rebuilding an AS-2518-35
Post by: SirPeale on March 07, 2010, 02:57:26 pm
I always do this when removing ICs.  I was just trying to salvage the existing ones.

Not wanting to damage the board further, I invested in a desoldering iron.  An Aoyue 474A+.  It had been recommended on the KLOV repair boards with glowing reviews.  Very reasonably priced unit, so I picked it up.

I wish I'd gotten one years ago.  What would have taken me an hour to remove ONE chip with a sucker and braid took me the same time to do the entire board.  Amazing.  And the pads are so clean and shiny because it sucked up all the gunk.

You'll note the thread title has changed.  I (stupidly) looked at the board and thought "oh hey!  AS-2518-35!" for the sole reason of the battery.  When I pulled up the schematics, of course they're completely different!

The schematics for the MPU-1 are here: http://files.pinball-fixers.com/gameplan/MPU_Schematic_(MPU-1).pdf. (http://files.pinball-fixers.com/gameplan/MPU_Schematic_(MPU-1).pdf.)  Trying to identify the chip @ U13.  When I removed it from the board nearly all the legs came with it.  All the other chips came off without complaint.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: lilshawn on March 07, 2010, 03:38:27 pm
coolsville dady-o!  ;D

still trying to drop the hint to get the boss to pick up a de-soldering station for at the shop...the ammount of re-working we end up doing would make it worthwhile...guess for now we will stick with the old solda-pult.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on March 07, 2010, 05:56:40 pm
It was like $135 shipped.  The money you'll save in time alone makes it worth the purchase price.  If your time is worthless, then this machine is not for you.

Heck, get one just for yourself and use it at the shop.  Once your productivity picks up 1,000,000% he'll see how worthwhile it is.

Do get extra spring filters and sponge filters.  Extra tips wouldn't hurt either - I wore thru one already.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on March 08, 2010, 01:43:24 pm
I may have to just give up on this particular board.  The battery damage is very great.  So many traces missing.  I think it's even missing a few parts.  Hard to tell - some spots there are legs with nothing there, but often parts would be trimmed out.

There is a forum dedicated to people who restore Gameplan pins, I may ask them for advice.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on March 17, 2010, 12:27:07 pm
Finally got my shipment from Mouser and started in on repairs.

Rebuilding destroyed traces is such a pain.  Not so bad if there are just a couple, but there are many of them.

And I screwed up on ordering sockets.  I wanted .6" 28 pin sockets, but ordered .3" instead! 
Title: Re: Rebuilding a Gameplan MPU-1
Post by: lilshawn on March 17, 2010, 03:03:06 pm
you would think that since you are ordering .6 chips in quantity, that they would ask to make sure you wanted .3

oh well....

FOR SALE:......
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on March 17, 2010, 05:37:55 pm
you would think that since you are ordering .6 chips in quantity, that they would ask to make sure you wanted .3

oh well....

FOR SALE:......

I didn't order any chips, but refilled my socket supply.   Since I socketed the entire board (plus a Defender board I've been poking  @) I was nearly out.

No big deal, I've got more stuff to get.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on March 21, 2010, 07:39:32 am
Ordering the right parts seems to be a recurrent issue with you.....  ;D

I get 99% of them correct.  When you're entering in a laundry list of them, you're bound to make mistakes.

Tried rebuilding the missing traces today.
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on May 04, 2010, 04:34:35 pm
The edge connector is badly damaged, so I thought I'd employ the Bob Roberts edge connector rebuild trick.

Only problem is finding the connector itself (with the eyelets).  Anyone have a lead?  Preferably on Mouser?
Title: Re: Rebuilding a Gameplan MPU-1
Post by: SirPeale on May 10, 2010, 08:58:09 am
Replaced all the 4148 diodes yesterday.  Many of them broke in two when I tried to move them.