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!

Sound work on the Star Trip Pinball Table

Transistors on the SDU-1 (Solenoid Driver Unit)

I was pretty excited about the information detailed in this post and thought it would fix my Star Trip sound problem.

So I carefully unsoldered all 4 transistors and checked them.

All 4 were good....sigh.

After soldering them back in, I hoped something might have changed so I tried putting the board back in

And turned it on. The sound is still there......

Warning, the following short video has very annoying sound - this is what I am dealing with!

Putting the heads on

After the move it was time to put the heads back on.

Unlike newer pinball tables which have a hinge for ease of transport, mine need to be disconnected and unbolted. Since all of the electronics and power are in the head, there are a LOT of cables.

The Hot Tip pinball, being a few years older should have been harder to disconnect. In fact it was the opposite, the Hot Tip table has snap connectors for every cable running between the two cabinets.
 


The globetrotters pinball does not. Each wire runs up from the base and directly to a board connecting to a board-edge connector.

So, after disconnecting everything it was time to pull the bolts.




Reversing the process was a lot harder. While keeping the door open, we had to hold the head up so the cables could be fished through the hole in the bottom. Then trying to move it around to find where the holes lined up - all without damaging anything!

Moving day

Posting has been thin lately primarily due to how difficult it has been to work on the tables. After the rains set in, the stuff from the back yard moved in to the garage and my workspace became extremely crowded. Here is a picture of how it has been.

 Note the workbench itself, imagine trying to spread out your documentation, soldering, boards and parts. Part of that is an excuse, as I need to get better organized.

Originally the plan was to keep the tables in the garage, then during summer parties we would have the pingpong table and the pinball tables set up and it would make for some fun gettogethers.  But I started thinking about moving the tables inside. Out in the unheated garage during the snowy winter did not sound like a good idea, either for the tables or for my working on them.

In the end, I moved them up to the bonus room over the garage. Warm, lots of space and a much more pleasant environment. There are a couple of things I am worried about though...

With carpeting, I am a little nervous that I will get oil or black dust or something that will ruin the carpet. With it being inside the house, not sure that smelly things such as soldering will be well received by my wife. I may have to put a exhaust fan on the window or something.

But for now, it is almost ready and I can get back to working on them!