Gottlieb Bronco Pinball

Jan 19, 2007

Here's a very dirty Gottlieb Bronco. The cabinet and head have delamination of the wood and this has got to be the dirtiest machine I've ever seen. Looks like a massive cleanup project. The mechanics look ok but we'll find out later how bad the dirt has affected them. The backglass looks nice - some wear - some tape.

Gottlieb Bronco Pinball Head

The cabinet has caked on dirt and cigarette smoke. Also delamination along the edges which as broken off in some areas. I'm hoping to re-glue and preserve what's remaining and keeping the original paint.

Gottlieb Bronco Pinball Cabinet

Just look at this playfield... It was left in a dirty, and probably damp, environment for a long time. A couple of the plastics are cracked and the pop bumpy caps are worn. I'm hoping the plastics aren't dry rotted.

Gottlieb Bronco Pinball Dirty Playfield

Inside the box with the playfield removed. Hey - free parts from Radio Shack!

Gottlieb Bronco Pinbal Inside Cabinet

And the cabinet with the guts removed. Looks solid. A little vacuuming and a wipe down and away we go. I don't smell that musty 'left on a Florida back porch under a pile of stuff smell'. That's a good thing.

Gottlieb Bronco empty cabinet

Wow! Schematics - that's rare!!!

bronco schematics

Jan. 20, 2007

I always like to perform major repairs to confirm the machine will function prior to performing the entire playfield cleaning. Usually the primary repairs take only a couple of hours tops. In this case, the machine powered up but wouldn't credit or start properly, nor would it score or reset properly. Too many problems - usually this indicates one major problem. Because the machines was so dirty I decided to do a 100% check/clean on the bottom panel components.

Playfield Control Panel

I tested each solenoid by 'ohming' them out ( looking for 15-45 ohms ) and cleaning / adjusting all the contacts. I found 3 sections of the motor relay not making contact, and 2 other contacts among the various relays. I also found the '1st Ball Relay' was destroyed. This relay holds on for extended periods and will fail like, the main game hold coil, from extended heat. It just fell apart in my hands. To expedite the repair I borrowed the coin lockout coil from the front door and put it in place of the first ball relay.

First Ball Relay

After checking all the contacts and replacing the burned relay the game fired up normally. The score reels are sticking , as are the drop targets, and just about every playfield point needs cleaning and tuning but everything is functioning including the coin switches,credit, ball, and player counters. I'll do the tuning after cleaning the playfield - it's nasty.. Take a look at a small section before and after using a little 'Greased Lightning'... This will clean up just fine.

Pinball Playfield before and after Greased Lightning Degreaser

Jan. 22, 2007

The playfield cleaned up well. The dirt was so thick I could not see the areas where the ink had worn through to the wood. The areas under the pop bumpers was very bad although the pop bumper mylars were intact. Feeling the playfield I got the impression it had never been waxed nor cleaned while in use. The wear, overall, is quite normal for this vintage.

Clean Playfield

Here's the apron. It has so much embedded rust I figured it couldn't get worse. Worst case I'd have to re-paint it. I decided to dunk it in muriatic acid. The result was good. The rust was removed ( as was the undercoat paint on the bottom of the apron ) but the paint on top was left intact. I will leave this as is.

Here's a before shot:

pinball apron rusted

After the acid bath. The scarring is now bare metal instead of ugly rust brown.

pinball apron after acid

Here's a detailed shot showing the damage in the upper playfield.

upper playfield damage

Jan. 24, 2007 - boy this month went fast - wasn't it just New Year's Eve??

Here are the nasty old yellowed posts. Can't really do much except clean the dirt off. The yellowing is here to stay.

yellowed pinball posts

I don't know if this is the right name - Shroud or Apron - for this upper playfield piece of white metal. I had dunked it in the muriatic acid which did a great job on the rust spots but left the stickers in place. The stickers were not in good shape. I tried Goo Gone but couldn't get the adhesive to release.

I tried 'Goof Off' and got the label but also the paint. I had to repaint the entire shroud with flat white and then speckle with flat black from about 3 feet away. I compared my painted one to the other Gottlieb's I have and it's an exact match.

It's a shame I had to destroy the Gottlieb production label. I didn't even take a photo. Oh, well.

Pinball Upper Shroud

The original pop bumper caps broke their tabs on one side. I'm just leaving these for now. This is the reason alot of folks will glue a cap on. You can never get the glue off and you ruin the lower pop bumper body. My Mr. and Mrs. PacMan had glued caps.

cracked pop bumper caps

This machine was filthy. I don't think I've ever had to clean so much gunk. The underside of the playfield inserts were so dirty that after I cleaned them twice as much light passed through them.

cleaning the pinball playfield inserts

All the plastics were a little bent. Just heat them up and flatten with a phone book. 3 of the plastics are cracked. 2 were glued back together. They are all permanently yellowed.

flattening playfield plastics

Just as with the bottom panel I had to clean every playfield contact. Here's one of those wonderful Gottlieb relay racks. All cleaned up and ready to go.

playfield relay bank

I always save the score reels until last. These are the Gottlieb Decagon units. After disassembly and cleaning they all worked like new. I've only done player one. This will allow me to test the game fully. Also all of the connectors in the head and all relay contacts required cleaning to play reliably. The Gottlieb score reel ink will rub off with Windex so mostly I used mild soapy water.

player 1 score reels

Here is is to date. There were some additional intermittent problems caused by some mis-adjustments on the motor switches. Also all the back box relays were filthy and intermittent. This chime box had a broken coil which was repairable. It's very playable right now and I think I'll go play a few games and finish the rest of the score reels, back box lamps, and cabinet cleaning tomorrow..

Pinball almost ready

Feb 31, 2007

As you may be aware Florida was under tornado attack Thursday night. Fortunately it missed us but we know people near the affected areas who described it as 'the most concentrated thunder and lightning you've ever seen or heard'. This was followed by the tornados.

I seem to have lost the photos of the machine with the score reels complete and all back box lights. Not important. I take more when the game is re-assembled. Today's job was to finish giving the legs and some rusted metal an acid bath and deal with some cabinet issues so off comes the head, out comes the playfield and control board.

Now I'm dealing with the de-lamination of the cabinet and head. I could either re-surface the entire cabinet and paint - or (plan b) - just glue down the parts that are de-laminating. I settled for plan b.

Here's two shots of the repair. I spread the damaged wood and forced in some wood glue and clamped the mess together.

Gluing Lifted Laminate On Pinball Cabinet

And the bottom edges. I had to flip the cabinet upside down to keep the glue from running out as you can't squirt glue upward and have it stay. Because I clamped using wood it was important to make sure the glue on the surface was wipe with a damp cloth to prevent the clamping board from being glued to the cabinet. There is still that yellow staining below the siderails that I can't seem to get off with Greased Lightning. I'll look into that tomorrow when the glue dries.

Gluing Lifted Laminate On Pinball Cabinet

Feb. 3, 2007

After gluing down the loose laminate, It's now time to attempt to get rid of that ugly yellow coloring on the side of the pinball cabinet. This looks like yellowed top coat and isn't as easy to get off as cigarette smoke. It may even be a combination.

Yellowed Pinball Cabinent

Again, back to that wonderful 'Greased Lightning' (maybe I should seek an endorsement deal). In this application keep in mind Greased Lightning will eat the paint BUT has to be left on for, in some cases, 10-15 minutes to break through the yellowing. It took about 1 hour each side total. I've seen someone used brake cleaner and other more aggressive cleaners. I did not have any to try to I just let this stuff soak in.


After soaking with GL, leaving for 15 minutes, and wiping 3 times the cabinet finally came clean. If this was just plain cigarette smoke the GL would take it off in a few seconds. So now I've got a nice clean cabinet with normal wear marks instead of the peeling, flaking, yellow thing it was. If you look closely near the botton you'll see approx. 1/2 inch of top laminate that had been destroyed and left bare wood.

Yellowed Pinball Cabinet

Next up is the back glass. There's a lot of flaking in the brown areas and the taped pads used to keep the glass from banging against the score reel board have permanently damaged the areas of the backglass they're attached to.

Gottlieb Bronco Back GlassGottlieb Bronco Back Glass

Here you can see the cowboy's flaking brown pants, vest, and hand and the marks left by the taped pads. Some of the pads are in complex areas and would be worse if I tried to remove them. I just decided to brush off the loose dirt and wipe the glass, where I could safely, with windex. And then, Thanks to Marvin's Tips, I sprayed the glass and covered with Clingwrap. We'll see where we're at tomorrow.

Gottlieb Bronco Back GlassGottlieb Bronco Back Glass

The top of the head had been covered up with a piece of bent metal - like molding. Removing it revealed this missing piece of wood along the top. I'll deal with this another day when I get the saw out.

Broken Pinball Head Wood

Here's the cabinet and game to date. I think when it's all said and done the game might be worth a few hundred dollars. Adding up the hours and I think I would make something like $2.56 per hour. Not a very profitable endeavor! But I do enjoy it. I think if you're looking to buy you could buy one of these near mint for about $1500-$2500 - I just don't think this one will ever qualify for that.

Wed. Feb 7 2007

Everything's in place. This is about as far as I'm going on this at this point. I've soldered some of the lamp sockets and made some score cards. The broken wood on the head will get done later - I'll need to re-face the entire front of the head to make it look decent. To make this game look new at this point it'll need a full cabinet repaint, new plastics all around, some playfield inking and filling, and far too many things to make it worth my while. The game does, however, play great and it's pretty fast. It's a shame it's got no decent dollar value due to cosmetics. On to the Bally Hoo!

To Be Continued ???