a new computer table-top - Criteria

Working on the United Brazil wooden legs reminded me that other wood-related projects needed some attention.

The first revolves around my computer desk. My wife and I use our computers side by side. Her desk is an old heavy-duty office desk that weighs around 500 pounds, is solid oak and is chewed up pretty badly. Mine is a cheapie IKEA desk, with the surface all bubbled from too many cokes.

My first thought was to build a new custom table for the two of us, but I had 2 issues:

1. Making a rock-solid custom table or desk with drawers is a LOT of work - and not really needed since the two desks already work great.
2. We may be moving in a couple of years. Did I really want to put all of that work into something that would be torn out in 2 years?

For me, the answer was to create a new table "top" and lay it over the old ones. This had some advantages:

1. relatively cheap (a lot less wood)
2. relatively easy to do (basically just a table top)
3. can still be "custom" without being built-in (more later)

My design criteria:

1. must be a single piece of wood all the way across both current areas (about 13 feet wide)
2. must be rock solid (not slide around)
3. must be level (our desks are currently 1/4 inch off in height)
4. must have a coolness factor

United Brazil backglass artwork

Taking a break from digging around in the electronics of the United Brazil, I decided to tackle the other part of it that is in poor shape - the backglass.

In many cases, when a pinball backglass is old and the paint is flaking off, a new one can be purchased, either a replacement from eBay off another machine or from companies that specialize in creating replacement artworks.

In this case, the Brazil is quite rare and none of that is possible. Looking at the backglass, I decided to attempt to make a new graphic myself, filling in the missing pieces as best as I could.

I started looking for some reference images online, but there are only a couple and all are very low rez (less than 500 pixels wide) so they are pretty useless for this kind of work.

But I wanted to get started, I tried scanning the image on my flatbed scanner. It turns out the thickness of the glass puts it completely out of focus! It would have to be a camera then.

I set up my camera as close to 90 degrees as I could to prevent barrel distortion and took several high-res pics, then stitched them together in Photoshop resulting in a 6000x7000pixel image.

(small version)

Then I started fixing the "easy" stuff, the geometric shapes like circles and squares, the sky, etc.


I am slowly making progress, here is an example:

That area is complete. But down in the complex stuff it is a different story:

on the left is the original scan. On the right is the same area as it looks now, as you can see I have some of it done but the complex shapes like the building and the man walking are still to be done, and in some cases it is gone and I don't know what is supposed to be there. But it will end up being better than it was and I will still have the old one for any purist collectors.

It is a slow process. Things like the letters. In an effort to be authentic, I am scanning each letter individually. In many cases different versions of the same letter exist - a "T" doesn't look exactly the same everywhere, so I am assuming they were hand-drawn. Rather than just use a font I am doing my best to make it as perfect of a reproduction as I can.

Brazil Legs

(dated January 2017)

Leg refinishing the Brazil Pinball was pretty straightforward.

The legs are simple wood. I removed the fittings (bolts that held them to the table, the bottom spacers and the side bolts that prevented the wood from splitting) and threw them all into the tumbler for polishing.

The legs themselves were sanded down smooth to get rid of the old finish, scuff marks, etc.

I then put a couple of coats of stain on them and several coats of clear.

The bolts and parts came out of the tumbler looking like new and it all bolted back together just like it was supposed to.

With the legs on, I was able to remove the sawhorses and let it stand on its own!

Turning on the United Brazil

(dated December 2016)

I turned on the United Brazil pinball. Despite its good looks inside, nothing happened other than 2 lights came on. Still - that the lights came on indicated the power was good for at least part of it.

I checked the fuses - amazed at how little has changed. These are literally the exact same fuses I purchase now at the hardware store in a 60 year old machine. The fuse holders are the same, everything is the same except that since it dates before electronics, everything is individually wired with a wire.

The fuses looked good:

I located the schematic and dug out my multimeter. Initial results looked good, the power coming off the transformer seemed ok.

My problem is that the access panel to the power area is on the side of the unit. I need to get it moved into my workarea so I can easily get access.

In order to do that I need to get it off the sawhorses (I removed the legs for transport)

The wooden legs are in poor shape so rather than simply bolting them back on, I decided to refinish them and get them back to shape first.

United Brazil Bingo Pinball

(dated November 2016)

Today was a red-letter day! I spotted an ad for a "classic pinball machine" at a local shop and went to take a look. It was in surprisingly good shape, not like some:

And the price was good, real good. It looked like it might a restoration project.

On closer view it turned out to be a 1956 "United Brazil" Bingo Pinball machine: Original Brochure

and when we got it home and really got a look at it, other than the backglass, it was in pretty good shape:

Back Online

Well, its been awhile and I let this drift away. Going to start posting again and fill in because some interesting things have been happening.

Nightmare with a soldering gun

After 2 hours of work, I am still not finished removing the corroded and burnt parts from the power board on the Harlem Globetrotters table.

 The removal really highlights my lack of skill with a soldering gun and just how hard it is to do a decent job. Especially with the multi-pin connectors.

I started out removing the burnt fuse holders. This wasn't too bad, though the connectors were large and it was hard to unsolder them enough to pull them out.

Then I tried to do the connectors. After several passes with the solder-sucker there was still enough solder to keep them from coming out, so I had to try and heat all of the pins at the same time enough to pry out the connector with a screwdriver.

A complete nightmare. I had to hold the board with one had, hold the soldering gun with the other hand, hold the screwdriver with the third hand and try to pull on the board with the fourth hand.

Trying to unsolder all 8 pins at the same time didn't work, so I tried to unsolder a few and then pull the edge of the board up. Backbreaking work hunched over the board. The solder gun got so hot I couldn't hold it, the board got so hot it burned my fingers.. and after 2 hours of work I am still only partially finished.

Whats even worse is that I am destroying the board in the process.

As you can see from the pictures, it is not a very good looking board. Many of the pads that you are supposed to solder to are gone. My only saving grace is that this is the simplest easiest board there is. Giant traces 3/4 of an inch wide. several pins in a row all connected together.

I may be able to get this board working but it really shows just how hard doing board work really is.

Repairing the Globetrotters Power Board - stage 1

The Globetrotters power board is in bad shape. Scorch marks, burned components, missing pieces, etc.

However, the good news is that I can easily buy a replacement, so..... that makes it a perfect candidate for my first board reconstruction!

If you recall from the last entry, this is how the unit started.

Separating the board meant unsoldering each one of the wires:

But at last, I had it separated!

Unfortunately, my soldering skills are still not quite as good as they should be. But in my defense, removing the big Bridge Rectifiers (essentially big square boxes soldered to the board) is hard. All 4 contacts have to be heated simultaneously while the board is held in the second hand and the rectifier is extracted with the 3rd hand.

Anyway, as you can see, I managed to remove the little metal slots and pads where the solder wen through the board:

I still have the big connectors to remove and I need to check the resistors and diodes to see how they look, but I can't do that while they are under a layer of dirt and grime......so, into the bath they went!

After 1/2 hour in concentrated soap and with a light scrubbing from a delicate paint brush, the board looks much better:

Next step, remove the rest of the components I plan to replace (multi-pin connector and the fuse holders) then brush with a tougher brush (toothbrush)

Pulling the Globetrotters Rectifier Board

After my failure to get any power on the Harlem Globetrotters pinball, it was time to pull the power board out and take a look at it.

Step 1 was trying to get the large connector off. It had 40 years of accumulated rust and grit in it, took quite a bit of finesse to get it off without breaking anything.

I then started trying to pull the board off the nylon spacers but it would not budge.

That's when I noticed the the screws on the board went all the way through and out the back of the mounting plate

So there was nothing to do but pull the whole transformer and board off all in one piece. First the transformer shield came off - making me nervous - isn't there lethal voltage in those things?

I VERY carefully unscrewed and removed the unit, taking care not to touch the transformer at all

Then finally i was able to see the rectifier board up close. It definitely shows scorch marks. Looks like it is time to purchase some electronic parts!

First work on Harlem Globetrotters

After the move of the pinball tables, when I discovered that I was missing a circuit board in my Harlem Globetrotters table. I decided to purchase a replacement. The nice folks at Alltek make a replacement board, so I ordered one. It arrived today!

But - before installing it.....I read the manual!   and it said to make sure that the 5v power was correct so that I did not burn out my brand new board.

So I plugged the table in, turned it on and connected up my trusty multi-meter:

I got nothing... no voltage, no lights, no hum, no nothing.

At first I thought I had a blown fuse, but after looking at them, the fuses are all ok.

However, while looking closer at the fuses, I noticed my power board does not look too good:

There are a couple of burned looking spots. One big on up near the top that looks like something might be missing and another one down by the connector.

I unplugged everything, looks like it is time to do some power board checking!