Initial conditions

Directly from US I bought this Omega Race few years ago. Unfortunately the cab has been damaged during the transport but it’s complete and this is enough to decide to restore it. I didn’t take pics when the cab arrived because it was covered by other cabs. anyway you can understand the conditions through these pics

the grid picked a knock

metal edges are dirty but in decent conditions

This is a problem: edges on the back are completely “frayed” because of the humidity or I don’t know what

  the rest…

this is the most important problem:


the cabinet was splitting in two parts.

Bottom…

As usual I start from here. Bottom was curved due to the the 2 transformers weight.



First of all I restored the foot supports even if I decided to not use them (I usually use castors under my cabs with European dimensions).

1. I removed and cleaned the supports
2. I removed most of the rust
3. I combined the rust (protecting the support) with Neofer product
4. Then I painted them with a protective chrome effect paint

I removed, cleaned and made the same process to the metal profile.

 
Then I pointed my attention to  the back castors.

Then I used 2 wood panels. The first, smaller, to fill the curved part, the second to reinforce the structure.

Then I reassembled everything and mounted the new castors instead of the original foot.

Power section

Opening the cab this is what I found

I cleaned all parts

and replaced fuse holders.

Then I made the same with the Filter unit

… after…

finally…

Then I configured the MT-88 for EU (220V)


           

Back side

The back side has been quite complicated to restore. Edges were quite damaged and in general the MDF was compromised. First of all I removed all parts

This was the status of the edges (t-molding included but we will work on it later)

   
First of all I used wood putty for the bottom part and then I used waterproofing paint on all parts

then I modeled both putty and edges with sand paper

Then I used flatting for parquet in order to give back consistency to the MDF and then black paint.

… last parts…

Inside

As I told before the cab had some problems and needed to be reinforced. In several parts one of the side separated from the rest of the cab.


So I spent a night with glue and metal parts trying to reassemble the cab.  

In the mean time I cleaned some parts

After that I checked the electrical part. All voltages are ok in all steps: Before MT-88: 0k 220Vac After MT-88 and before MT-89: ok 125Vac, fluorescent lamps work properly After MT-89: ok After power regulator board: 5V OK, 12V for coin door and marquee ok, 12V for audio is 15V. I’ll check.            

Marquee and Speaker grid

Speaker grid had a catch but I could repair it with a hammer ahah


Then I cleaned and replaced the bulbs behind the marquee


Then I cleaned and de-rusted the upper part

and painted of course

Once everything was ready I re-assembled and switched on.

Yet another Coin door

yes… probably if I summed all the time spend restoring coin doors I could reach years…

Initial conditions. Not so good, sot so bad. First of all I removed all parts, Midway plate rivets included.

Then I used the usual abrasive sponge (I can’t translate better than this) on metal parts and prepared a couple of new bulbs.

Usual procedure for the frame and the main panel:

1. removing the paint
2. rust-fixing paint
3. flating
4. black paint

This is the result, trying to give the original aspect



Same for the panel…


THE END:    

Front glass

..nothing peculiar, just  a couple of points with black paint to cover some scratches…

CP Glass

One of the best things of this cabinet is the control panel glass.

I just cleaned the Plexiglas  and replaced the lamp only.

     

Black Light

Another peculiarity of this game is the black light. The cardboard behind the half-reflecting mirror has been drawn with fluorescent colors so the result is amazing!   In this case I had to replace both the starter and the ballast. It’s very hard to find a 110-130V ballast here in Europe, believe me!!!

CP

Control panel was very dirty and had some damages near the screws used to fix the panel to the cabinet.

I just cleaned all parts removing buttons, screws and spinner…

And I sprayed the knob with transparent paint


As I often say: not perfect but good enough…

       

Edges and T-molding

This cab hasn’t a real t-molding. It is made just rounding the edges and painting them in black. After years all these parts were damaged and I had do be drastic to have a good result. These were the conditions before any action

so I sanded all parts

and I smoothed using a flatting paint and sanding again


Internally I used a satin-black, glossy-black for the edges.

and that’s all.

Sides

both sides had a lot of scratches but I didn’t want to replace the original arts so I painted all around 😀 😀 😀 as usual I follower these steps: 1 sanding 2 flatting 3 sanding again 4 painting (several times)

Wood

First part closed, the “wood” is ready. Let’s go to have a look to the monitor and the PCB!!

PCB – part 1

This was the PCB


So the acid made its job. The board had been socketed already


But I realized the entity of the damages once I removed such those sockets!

And I decided to dedicated a lot of time to remove all damaged parts


This is the board now

…even if some tracks have gone


Now I’m keeping pictures place by place so resocketing the board I can check which track works and which not.      

PCB – part 2

Once cleaned all damaged parts I made photos of each chip position in order to always have a visual representation of the trucks behind the new sockets. I signed the IC position and it’s location on the PCB. Here some examples:  

Then I socketed and replaced resistors and filters.


And then Kynar Wire!

 
Plugging the board I had a good surprise because the game started BUT after few seconds the vectors hide for a while. Running the self test I have the following errors:

• BBU RAM S4: BAD
• V RAM2 J1 and or (L/M)1: BAD
• V RAM4 (J/K)1 and/or (N/P)1: BAD
• V ROM2 F1: BAD

Actually not so bad.   All the  RAMs/ROM (but BBU RAM) share the VECTOR ADDRESS BUS, from SMEM0 to SMEM9 controlled by 74157 in positions K3, L3, M3.   MAIN ADDRESS BUS (MA0..9) and PROGRAM ADDRESS BUS (SEQA0..9) are connected to these 74157   I can see BBU RAM (5101) uses the MAIN ADDRESS BUS too, so I’ll check if S4 pins 1, 2, 3, 4, 5, 6, 7 and 21 are correctly on the bus and if all lines arrive to 74244 in (P/N)6 (pins 3, 5, 7, 9, 12, 14,16,18). This will be the first test I’ll perform.

Tools: Kynar Wrapping Wire

Kynar wrapping wire is used to repair broken PCB tracks or to make wire wrap; in this case you can use a dedicated tool to wrap the wire around the pins. With this special kind of wire you can perform extreme PCB repairs…  

PCB – part 3

Here the problems I had yesterday.

1. BBU RAM S4: BAD
2. V RAM2 J1 and or (L/M)1: BAD
3. V RAM4 (J/K)1 and/or (N/P)1: BAD
4. V ROM2 F1: BAD

 
1 – It was related to a power problem. I can’t understand connecting the oscilloscope ground to the game ground the probe wire becomes hot. Anyway problem solved.    
2 – V RAM2: This was the most complex error. The analysis made yesterday had no success but considering now the problem was related to J1 and or (L/M)1 only I pointed my attention to the “Chip enable” circuit. After some tests I could see I forgot to rebuild the track between 7404 in position PR1 PIN 8 to 7432 in position R1 pin 10.


3 – V RAM4: (J/K)1 2114 was faulty. I just replaced it.  
4 – V ROM2 F1: ROM was actually bad and I replaced it with a new one.   This is the self-test result. I’m sorry I didn’t manage Z signal 😀 😀 😀



so, PCB now is ok…   What have I to do now?

• No sound to the right speaker
• Monitor (not working)
• Back panel

Sound and Monitor

Sound now works properly. I had to clean the speaker contacts. About the monitor: It is in very good shape.

Plugging it to the cab I had the spot killer on and no lights on the neck. I cleaned all connectors but it was not sufficient. Then I realized that moving the cables I had some reactions and I checked the connectors solders and the red one on the main board connecting it to the HV unit has at least 5 pins interrupted. So 10 minutes with a solder and I remade the board like new.

 

Assembling the monitor inside the cabinet and cleaning the yellow layer and the black cardboard I can say most of the job has been done…

Most of the job has been done. Now the back panel is missing. Actually I don’t remember if I have it somewhere in my garage or I have to remake it. We will talk about this next week.

Back panel

I found the back panel and after a fast clean and repaint I could complete the cabinet.