Schematic Input

Just got this input regarding some of my notation questions from "CWatters"
on the sci.electonics.repair forum. Good stuff.

> "A.Grnd" - From J4 (A4) - (Is that 'all ground'?)

Probably Analog ground - perhaps for joystick potentiometer or speaker.

> "V.Batt" - From J4 (A5) - (Something battery?)

Battery Voltage.

> "Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?)

Logic Ground - eg seperate to Analog ground so as not to put digital noise
on the analog signals via a common ground.

Normally Logic Ground and Analog ground are connected together at only one
point somewhere. That point is usually either in the power supply or
somewhere where digital and analog worlds meet eg near the input of any
analog to digital converter or preamp.

Schematic Needed

I cannot seem to locate a schematic for the power supply PCB. Apparently this was not included in the original manual. I have the cabinet wiring schematic, but cannot locate one for the PCB.

$cared $tiff

I am starting to see visions of a good deal of green going out to make this project happen, so on a lark I have added a "Donate" feature in the sidebar. Donate and help save Tron from the evil MCP. Are you with Sark or are you with us?

Testy, Testy....

I decided to test the voltages being output by the power supply PCB. Overall they look fine. There are two a bit out of range;

Schematic Label: Coin door lights
Schematic Voltage: +12V
Recorded Voltage: +10.62V

Schematic Label: Coin Meter
Schematic Voltage: +5V Unreg
Recorded Voltage: +10.28V

The rest looked good. I am putting the word out to find out about the two descrepancies and find out the answer to some new dumb questions regarding various schematic labels. One is the "Unreg" notation on the coin meter location. Not sure what that means.

Others are:


"A.Grnd" - From J4 (A4) - (Is that 'all ground'?)
"V.Batt" - From J4 (A5) - (Something battery?)
"Logic Grnd" - From J4 (A2)(B3)(C3) and J5 (B4) - (Special Ground?)
"Reset" - From J4 (C3) - (I heard a rumor that this wire was key?)
"Unreg" - From J5 (A1) - (Unregulated?What does that indicate?)


Note the "J4"and "J5" indicate the connector, the (letter/number) code indicates the position as noted on the tables here: PS Test Results Table

AHA!

I found that the 12V output from the isolation transformer was good up to the
3 bank fuse clip. Not so on the other side. Placing the lead from the VOM
on the fuse itself reads 12V, but various parts of the clip do not. It is
also reading 1V or less at the molex to the power supply. This is 12V that
needs to go to the linear power supply. It was getting less than 1V. I am
replacing that fuse clip

You can see a pic of the fuse bank here, it is index #3 on the Tron Fuses page.

Also, Bob Roberts had an awesome tip on his site. If you are like me and
you are using "curling iron" soldering irons, you know removing old solder
takes for ever. Bob writes that you should melt a little new solder on
first, then remove the old. It works like a champ! Thanks Bob!

WG19k4906 Manuals Found

The Arcade community is the greatest. It always seems you are just one day away from the asnwers or resources you need. A responder from Vectorlist (Rasterlist) came through as did MonitorGuru from BYOAC with a link to WG19k4906 manuals, schematics, and flowcharts.

Monitor Troubleshooting

I decided to trace the monitor voltages to see why I am getting no juice
there. Earlier I detected very small voltages at the molex leading to the
monitor. Either I had my VOM on DC or the cab was off when I first tested
as I am now seeing 120V to the monitor.

The monitor does nothing though. I see now there is yet another fuse on the
chassis. It is hardwired and looks like the entire monitor needs to be
pulled in order to replace it. Ugh.

Need a k4900 (WG 19k4906) monitor manual if anyone has one for download. If
it matters, I have the model WITH the vert dampener.

james at retroblast dot com

Picture Problems?

I had at least one report that one or more pics were not loading correctly.
If you happen to see this please leave a comment and I will look into it
further. (This post is really just an excuse to test out the email posting
fuction of this blog). Seriously though, please leave a comment if you have
a problem on the site, it will notify me via email. Thanks.

More Power Options

It appears Bob Roberts sells some repair kits for the Tron power components as well such as a kit for the Midway 90412 Power Supply. Something else to keep in mind.

Tron OEM PS connector repair kit $12.50
Tron & others OEM PS (90412) Repair Kit $22.95
Midway (MCR) Capacitor 55,000uf 25v $15.00

MCR Switcher Adapter

I received some feedback regarding the MCR Switcher Adapter from Wizzes Workshop.

I am also noticing it was used in a couple of other Tron restorations.

I am going to keep plugging away for now, but will keep it in mind as I do have a spare switching power supply around here somewhere.

(This is the denial phase)

Pictures of the Power Supply

Some great folks at RGVA* are helping me figure out Tron's lack of get up and go. Someone asked to see some up close pics of the power supply and here they are:

An overall picture of the power supply - Note: The fuzz and grit you see around the bottom has been cleaned out via canned spray and a shop vac.

Close-up picture of the fuse clips and distribution blocks - Note: Yes the power is OFF in this one...

Also note that there are more power supply pics available via the "Tron Fuses" link in the sidebar. They are smaller, but cover more components. If there is a specific one you need to see in high res just drop me a line by adding a comment below.

No Go-Go Juice! The MCP Wins the First Round!

After carefully studying the manual and checking the location of all needed fuses, I found that all were gone except one. There are eight fuses altogether. The one that WAS there was of course the wrong one.

To be sure I was on the right track with my shopping list, I posted the a few questions to RGVA* to make sure I was not making a dumb mistake. Fuses are there for a reason and I want them to do thier job (as in to protect me and the cabinet in that order!)

The RGVA* folks came through and I was on my way. Here is the table I made showing the location of the fuses and the correct specifications for each one. I ended up getting mine at ACK SUPPLY here in Atlanta.

Go Here to Learn More About Tron Fuses Than You Ever Wanted To Know

First Pics

I took a bunch of pictures just before I loaded it up. This is the state in which I found this poor thing.

See First Pics Here

Rescue Tron!

Well, here we go. I saved a Tron upright from a slow death in local warehouse. The cabinet has quite a few issues and I originally intended to part it out, but the game has captured my interest. I think this will be an interesting build and this is my first dedicated arcade game restoration so I am starting this page to document the process. Ready? Let's get started!