Friday, July 16, 2010

SuperSprint Repair - Pt 3 - Power supply circuit

My parts arrived last night, and that means that the Super Sprint might be about to open her eyes for the first time in 10 years.  To be replaced are a 3.3ohm resistor (R601), a horizontal output transistor (2SD870), and voltage regulator (STR380).

Fig1 - The new parts

First, we replace the horizontal output transistor (HOT)

Then the voltage regulator. That's the quarter sized component
located in the square metal box.

And last, the open power resistor (3.3ohm, 10W) that sits between the rectifier and
the voltage regulator. In this picture, that's the smaller white rectangular
component bolted to the chassis on the right.

With the repairs completed, it's time for a power on test. And......  No joy.
Quite the opposite in fact. The large power resistor (R503 - 180ohm, 25W)
became very hot and the output transistor blew again. Looks like it's the
flyback after all.  Now to go find one of those. Man is working on 30yr
old technology a challenge...

EDIT: Found a reproduction K4900 flyback thanks to Chad at ArcadeCup.

If you've made it this far in the series, you're probably a geek. If so, you can find the technical details of the repair on the KLOV forum

Thursday, July 15, 2010

Golden Tee '97 - A new project for the Arcade

Not quite sure what I'm going to do with this one yet.  Might refinish it, might part it out, might sell it.  Whatever happens, here is my newest project.

Fig. 1- The new machine

Fig. 2 - The control panel needs a little work and someone murdered the coin acceptor trying to make it play.

Fig 3 - Left side

Fig 4 - Wells Gardner 25K7131 monitor works perfectly.

Fig 5 - Rear view of the coin mechs and bill acceptor.  Obviously one coin acceptor is badly damaged by efforts to make it free play.

Fig 6 - Cabinet needs some work

Fig 7 - The serial plate

To be continued.....

Foosball Table rejuvenation

Today my wife calls and tells me to pickup a foosball table she bought on Craigslist for $25. Expecting a WalMart Christmas toy, I do my husbandly duty. When I arrive, I am surprised to see a rather nice looking table that hasn't been cared for.  The play surface is practically new, and the cabinet shows little sign of wear, except for some scratches.  But, the legs are loose, the top is racked, and one end comes off completely when you try and lift it. Most of the damage came from not tightening the leg bolts and letting the glue joints take the load for mechanical fasteners.  Since I'm a woodworker, I can see that she needs some TLC but is far from a lost cause.  Here's what followed over the next few hours;

Fig 1 - Taking the table apart
Notice the cabinet end laying in the floor?  No tools neccessary to remove it...

Fig 2 - The Leg Brackets
Almost all of the brackets were removed, pre-drilled for screws, glued with polyurethane glue (Gorilla Glue), and reattached. This picture shows on after reattachment.  Shortly after this picture was taken, polyurethane foam would bubble out these T-nut holes.  Messy cleanup....

Fig 3 - The playfield
The playfield was flat and supported by these MDF struts, but as designed it could easily warp in the future..  I removed them, reattaching them edgewise with with glue and screws and "clamped" them to a smooth flat surface. Once dry, this playfield will remain flat for a long time.  It was attached with drywall screws but will be reattached with proper furniture screws.

Fig 4 - The end plates
One plate (shown) required a lot of work to get right.  Brads were used for fasteners, and the glue appeared to be hot glue?!?  All joins were broken, cleaned, and reassembled with poly glue and screws.

Fig 5 - Reassembly
During reassembly, all joints were clamped to keep them flush and tight.  This will result in a cabinet that is tight with no gaps.Many bolts were completely missing and had to be replaced.

Fig 6 & 7 - The end result
Now back together the table is tight and solid.  Total costs was about $5 worth of parts and glue (all on hand) and about 3 hours time.

So was it worth it?  I think so.  For $30 and a few hours work, we got a great looking foosball table that retails for $475 new.

Tuesday, July 13, 2010

SuperSprint Repair - Pt 2 - Installing a cap kit

With the monitor removed and on the bench, the repairs begin.

Fig 1 - Game disassembly

Diagnostics indicate that the chassis has several problems.  At the least, it needs a new power resistor (R601, 3.3ohm 10 W), horizontal output transistor (HOT - Q352, 2SD870), and "cap kit"

Fig 2- Well Gardner 19K4915 Medium Resolution Chassis

First, we install a "cap kit".  This means that we replace all the electrolytic capacitors that may have dried out with age.  In the pictures below, these are the little black can shaped components

Fig 3 - Getting Started

With the cap kit installed, it's time to double check my work and resolder any connections that look iffy

Figure 2 - Chassis Board solder side.

More parts are on order, so the next steps will have to wait for now.  In our next installment, I'll install a new horizontal output transistor (HOT), power resistor and voltage regulator.

SuperSprint Repair - Part 1 - It begins....

Many years ago, I purchased an Atari Super Sprint arcade game. It entertained visitors at my house in Stone Mountain for years, including one all night "drinking and driving" marathon.  Sadly one day the screen of this beloved game suddenly went dark.

The game will play "in the blind", but basic troubleshooting (fuses, power) revealed little other than the monitor was the not working.  So, I hauled the monitor off to an arcade repair shop where they declared the monitor chassis dead,unrepairable, and parts unavailable (it is a 1982 machine, after all).  After 2-3 unsuccessful attempts to purchase parts off eBay, it appeared my Super Sprint was doomed to stay dark forever.

About that time, I got engaged to my beautiful bride Michele, and video games took a back seat to weddings, houses, and picket fences.  During the move, my Super Sprint got relegated to the corner of my new workshop where it would sit for almost 10 years....

Recently during the process of converting an old Mortal Kombat arcade cabinet to run MAME, and discovered an active community of arcade collectors who repair and restore classic arcade games like. With their guidance and experience, I hope to repair my Super Sprint game so it can once again entertain family and friends. This series or articles will document the repair/restoration process as it unfolds.