The DMD, Part III

The DMD controller failed again yesterday. This time it went with a bang and scared the hell out of a friend playing the machine.

At first it seemed that only the fuse failed, but after replacing it, the display looked really really weird. No letters, no graphics, just some sort of huge blob in the middle. I measured the voltages (Again) and the two negative voltages were waaaaaay of the normal readings. They read -152/-130.


What am I going to do about this one? I don't know yet. I'll see in a couple of weeks, when I'm back with my Whitewater.

It seems that if things continue to evolve in this manner I'll have to start a new blog and dedicate it to DMD controller exclusively. :)

Broken switches

Now that the DMD works again I checked out the whole bunch of broken switches that the self diagnostics reported.

Result: All of them actually work.

I guess my dad was playing and hit very little switches in a whole lot of games :).
Must I add that he is not a very good pinball player.

The DMD, Part II

I came back home today and naturally the first thing to do was to fire my whitewater.

To my surprise, here's what I found:

Now that's something that puts my soldering skills to trial. I started dealing with this issue immediately, so the first thing i did was to measure the voltages again. The two negative voltages were perfect this time (-118 and -106). The wrong one was +62 which read only 24 volts. Here's what pinrepair has to say about too low +62 voltage:

"The +62 volts is not +62 volts.
On WPC-S and earlier games, the positive DC voltage trace that comes from a very small bridge rectifier BR1 is physically routed underneath resistor R9 (1.8k 5 watt resistor). Because of the heat generated by this 5 watt resistor, and the current drawn from the bridge rectifier, this circuit board trace can become burnt and break underneath resistor R9. Because the trace physically runs under this resistor, the broken trace can be hard to see. "

And here's what my controller looked like:

Apparently this is exactly what happened to my board. I consulted the enclosed board schematics and here's the solution I came up with:

The DMD lightened up and I was really thrilled until I noticed that some sparks are flying around the board. It' seemed as that the cable I soldered on to the resistor was to close to the heat sink. I quickly turned the machine off. The board worked, so no other components were burned. I just had to replace the missing trace in some other way.

My second attempt looks like this:


And here's the result:

No sparks this time. I guess it's playing time again and let's see what the testing will bring.

Fun, fun, fun

After quick-fixing the both faulty switches I decided that it is not the time to begin with the other repairs or even cleaning yet.
I just didn't feel like it, so I ended up playing, playing, playing and then playing some more.
Man, this pinball is fun. Even though it is horribly dirty, the switches are all wrong and some ramps are not quite as they are supposed to be, it is so much fun it's almost criminal. This gotta be some of the best layed out playfields ever.
I can't remember ever having this much fun with the Hurricane. Thank goodness I got it back.

Analysis

Let me start with a picture.

Here it is. My white water.
Finally I'm back with it and I have some time on my hands to examine it closely. Naturally, the first thing to do is to install the DMD controller and check what the self diagnostics have to say.
Here's what came up:
* Check switch 57 - Canyon main
* Check switch 73 - Hot foot upper
Looks pretty good. It might be in better shape than I anticipated. A closer look showed that a couple of solder joints are broken. Piece of cake.

What about the other stuff? Here's what i found up:

1. Faded right side of the cabinet

I don't know what I'm going to do about this one. Perhaps one day, I'll invest in new decals.

2. Only four working waterfall ramps
I guess replacing the bulbs should do it. The current bulbs are not #194 , but some sort of weird 12V car light bulbs. No wonder they're all broken.

3. Broken (and horribly fixed) disaster drop ramp

Luckily the missing bit was still inside the cabinet. I guess some gluing and installing a ramp protectors will do the job.

4. Broken bigfoot ramp

I' guess I'll have to improvise here a bit.

5. Wrong lock switches, wrong hot foot switches

I'll order the correct ones if I'm able to find them

6. Broken plastics on the boulder garden

I'll order the new ones, if I find a store that sells them separately

7. Bigfoot's head is not spinning
It seems that motor is spinning and that the optos are working. Looks like just the head isn't attached properly.

8. Broken light kickback switch

I also find this one inside the cabinet. I'll try to glue it back

9. Some weak solenoids
Some cleaning should fix this ones.

10. Some rubber rings are missing, the others are in quite a bad shape.
I'll just replace them all

11. Very, very dirty
I'll put it to pieces an clean it thoroughly.

The DMD

The first to deal with on my journey of bringing White water back to life was its non working display. We all now that display is a important part of every pinball, but you can't really tell how important, until one is actually gone. Imagine. No self diagnostic, no error reports, no tests, no settings, no score, nothing. Anyway, it was obvious that this is going to be the first issue to address in order to move anywhere.

The symptoms.
The DMD was not completely dead. It showed some life, but only around the edges and even there it was barely lit (again, no picture :(). It seemed that picture was getting through, but there just wasn't enough power to display it.

The diagnostics
Luckily I still had my Star trek at hand (loaded and ready to transport), so naturally, the first thing I tried was plugging the White water's DMD into Star trek. The thing worked and a 180€ that a new display would have cost me was saved. Since the display itself was flawless, there was only one remaining option left. There had to be something wrong with the Dot Matrix controller. After re seating all the cables that come from the controller a couple of times didn't worked I grabbed my multimeter to measure the voltages that come from the controller which gave me some answers. The first two pins read only -75/-63v while it should be at least -115 / -103.
The reason for non working display therefore is: Too low negative voltage produced by the dot matrix controller.
At this point I had to leave for Ljubljana where I live and work, so I just packed the controller and some tools and took the stuff with me. Unfortunately it'll have to pass a couple of weeks before I'll be able to work on White water again, but at least I'll try to get the controller in order till then.

The cure
The problem was solved by rebuilding the enitire high voltage section of the DMD controller.
Here are some pics.

1. The DMD controller


2. The (faulty) high voltage section


3. The shopping list


4. Printout from pinrepair


5. The tools used


6. HV section without components :)


7. Garbage


8. and finally... freshly rebuild HV section



The test
It's a good thing that I recently moved my Star Trek here to Ljubljana, so I was able to test my four hour hard work.
Here's the result, after switching the controllers:
HOORAY! The thing works.

Let me add that this was my first real attempt at PCB soldering, so I'm really really proud about the result.


The thanks
www.pinrepair.com. I'd be doomed without this site.

The Beginning

What to say in my first blog?

I guess it would be nice to introduce myself briefly.
Well. I'm 31, I'm a computer engineer from Slovenia and I love Pinball.
I guess I'm a Pinball lover ever since I can remember. My Pinball playing days go way back to early 90's where I spent most of my pocket money playing Funhouse in a local bar.
This passion got me into buying my first pinball machine in 2002. It was a 1992 Williams White Water, that paved the road to my pinball repairing knowledge. I kept it for a couple of years and then a exchanged for a Hurricane. What a mistake it was. After a while, Hurricane turned into a dust shelve and I kinda forgot about playing pinball.
My passion reignited in the end of 2008 when a friend of mine got himself The Addams Family. It remembered me how much fun pinball actually is so I wiped the dust of the Hurricane and started to play again. I also started tracking the Slovenian pinball market and soon I found just the thing for me. It was a pretty beat up 1993 Star trek the next generation at a very decent price. I bought it and it took me almost half a year to rebuild it completely. Unfortunately it didn't occur to me that restoring it would be a nice topic for blog but anyway. I'll try to make it up with this one.

The story that I'll try to cover here begins a couple of weeks ago when me and a friend of mine decided to check out all the bars in our region that used to have pinballs to see if there are any left. About hour or so into the action we entered a bar in Dravograd and stumbled upon a sad scene. Unfortunately I didn't take a picture of it, but there it was. 1992 Williams White Water, all dusty, dirty and broken. After a close examination I realized that it is not just any White water but THE White water, my actual first pinball. I instantly decided that I want it back, no matter what. So I called the guy and I asked him if he wants his Hurricane back. He just said: "Sure, no problem".

A week later White water was back where it belongs. In my basement.

And this is where this blog begins. I'll do my best to cover all the aspects of getting a pinball that was very poorly taken care for back into top playing condition.

Wish me luck ;).