• [Article 6128]Omega Race (2) :: Yet another Coin door


    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:




  • [Article 6107]Omega Race (2) :: 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.








  • [Article 6076]Omega Race (2) :: 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)

    omegarace_0404 omegarace_0403



    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…

  • [Article 6026]Omega Race (2) :: 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.


  • [Article 6012]Omega Race (2) :: 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 picjed a knock
    the grid picjed a knock
    metal edges are dirty but in decent conditions
    metal edges are dirty but in decent conditions
    THis is a problem: edges on the back are completely "frayed" because of the umidity or I don't know what
    THis is a problem: edges on the back are completely “frayed” because of the umidity or I don’t know what


    the rest…

    this is the most important problem:

    the cabinet was splitting in two parts.


  • [Article 6003]ARCADEITALIA 2016

    Prima di intervenire su un cab è importante capire quali interventi fare. Può essere utile stilare una check list con i punti di interesse poi da sistemare nell’ordine più opportuno. Solitamente procedo come segue:

    1. Parte interna del mobile (legno, plastiche, metallo, …)
    2. Fondo
    3. Cablaggio interno e alimentazioni
    4. Monitor (pulizia e sistemazione)
    5. Parte posteriore e back panel
    6. Mobile esterno
    7. Coin door
    8. Comandi
    9. Scheda e Monitor (parti elettroniche)

    So che proceduralmente mettere in fondo la sistemazione della scheda può sembrare anomalo, ma dopo molti anni ho capito che se il gioco è funzionante la mia soglia di “restauro accettabile” si abbassa molto, quindi per evitare la tentazione di archiviare il progetto come finito e passare ad altro preferisco tenerlo non funzionante fino alla fine.

    Le parti di un cab possono essere identificate secondo diversi criteri; io lavoro su una matrice che prima di tutto seleziona le tipologie di materiali o tipologie funzionali:

    1. Legno
    2. Metallo
    3. Plastica
    4. Vetro
    5. Carta
    6. Comandi
    7. Cablaggi (rete, alta tensione, bassa tensione)
    8. Alimentazione
    9. TV
    10. Audio
    11. Gioco
    12. Eventuali altre parti

    Ognuna di queste categorie può riguardare l’interno o l’esterno del mobile. Questa differenza è fondamentale perché le parti interne non sono soggette a usura diretta e inoltre solitamente non sono a vista (a prescindere dal cardboard o altre poche parti)

    Tecnicamente ogni singolo punto identificato dall’incrocio di queste due liste potrebbero essere affrontate con tecniche, strumenti e metodi differenti.

    Ecco una sommaria matrice di identificazione dei punti di restauro.

    Oggetto dell’intervento



    LEGNO Side art

    Parte frontale

    Parte superiore

    Parte posteriore fissa

    Back panel


    Altre parti (pannelli ecc.)

    Interni invisibili

    Interni visibili

    METALLO Control panel

    Viti in genere

    Coin door

    Cash door


    Interno della gettoniera

    Cash box

    Staffe e sostegni

    Altre parti in metallo

    PLASTICA / VETRO T-molding

    Control panel


    Vetro anteriore

    Specchio semiriflettente
    CARTA Instruction card




    Altri comandi / FF

    sw e pot. interni
    CABLAGGIO DI RETE Cavo esterno di alimentazione Interruttore

    Filtro di rete



    Alimentazione TV

    CABLAGGIO BASSE TENSIONI Cab. basse tensioni

    Cab. altoparlanti

    Cab. video

    Cab. comandi

    ALIMENTAZIONE Trasformatori

    Schede di alimentazione

    TV Masse



    AUDIO Altoparlanti


    GIOCO Scheda / Schede




  • [Article 5970]Super Bug :: Board troubleshooting (Car)

    During the last party (VMASP_2016) this game became to have a problem to the car sprite.


    A “black” bar was in the center of the car. Actually that part of car was missing so we had a sort of “transparency”…

    First of all I removed the mask prom for that sprite having a confirmation that something was going wrong with the vertical signal that identifies the sprite zone to draw


    This part is shown on the schematics and you can see H and V are controlled by the same flip-flop.


    In fact checking the signal to the  7474 pin 6 in M7 I had the following waveform (very similar to the problem I had on the screen)


    I was quite sure H and V signals were ok (in any case I made a check)  and so I replaced the 7474 having, now, this waveform.


    Definitely better…

    Plugging the board I had this pattern


    and resocketing the PROM I could verify the problem had been solved.


    .. mission complete!


  • [Article 5947]Defender :: Hacking 19-in-1

    I was quite scared about the possibility my Williams boardset could fall while people was playing.

    So I decided to plug in the (famous) 19-in-1 board, because I could see the game is very well emulated. But just see and not play, because once I received the board I discovered in half a minute that BUTTON 5 (S5) is supported by software but not by hardware (actually button 5 and 6 for both players). This button is needed because corresponds to the HYPERSPACE button.

    Setup shows both buttons 5 and 6, it means who wrote the sw wanted to use them and probably he allocated in the right way the specific resources.

    Backtracking all inputs I could see all of them arrive to the 74244 close to the JAMMA connector, with the exception of P1S5, P1S6, P2S5, P2S6.

    There are 5 74244 and I discovered that S6 for both players are anyway connected to these buffers but part of the the pull-up circuit misses (and the connection to the JAMMA of course). On the contrary no way to intercept S5.

    So I moved to the bus tranceivers (74245) between RAM and FLASH. If buttons are managed, they are managed there (!!)

    Playing a little bit with +5 power and using my finger I could change the status of P1S5 and P2S5. This means that S5 signals are undetermined.


    defender_19in1_02 defender_19in1_01



    Using a pin (pulled up with a wire connected to the pull-up pin of JP1) I touched the pins waiting for a reaction related to the involved buttons and the PIN 3 of U22 (one of the two 74245) was what I was looking for. So I had to start from there.


    First of all I connected a wire to the data-bus on the PIN3 of U22


    Then I used a 74244 to complete the circuit.

    PIN 10 to JAMMA ground

    PIN 20 to JAMMA +5V

    PIN 16 to the databus

    PIN 4 to JAMMA Component side PIN 26 and to a 10K resistor; this resistor then is connected to +5V

    PIN 1 to PIN1 of U30; in fact this board uses 4 different signals to enable the input drivers and I tried with the one dedicated to PLAYER1 and his buttons. Just a try.



    I’m sorry I haven’t any tool to manage SMD components and boards so my soldering is very bad.

    Anyway this is the result:



    fixed with some hot glue




    It works great and now I have a good board backup 😀

    PS reading this post I can see my English is very bad; I’m sorry for that. If you have any question please don’t hesitate to contact me.

  • [Article 5928]Circus :: PCB SK2 Troubleshooting (2)

    What I know about this problem is that connecting to ground the PIN 1 of the 74H21 in position 15D (signal MVID) I have the game running with a correct attract mode, the spinner works, accepts coins and the game starts. The problem is (obviously) that the “MAN” is missing; in fact that signal manages the jumping man.


    So I had a look to the “MAN” circuit but after some evenings replacing components I replaced ALL components but nothing changed….


    All IN signals seem to be OK.

    Now I’m blocked, I can’t solve this problem.

  • [Article 5922]Circus :: PCB SK2 Troubleshooting (1)

    I want 2 boards for each cabinet I have; that’s because in case of problems I can continue to play my games until the main board has been repaired. So I found an original EXIDY CIRCUS board, sound board included. Actually when I tested it I could see garbage on screen but I could insert coins and “play”.

    I tested this board on my cabinet:


    I pointed out directly to the RAMs and related components. After replacing a couple of RAMS I had this result:


    I needed a bit of time (wasting time to replace components into the video section) to understand the problem:



    Cutting all pins I could reach this status:


    A good result, but not enough. In fact the game freezes after few frames.


  • [Article 5916]Turbo :: Free Play

    Thanks to Matt Osborn I installed the FREE PLAY eprom on my boardsets; very easy job and great result? Are you interested in this modification including the save kit?, please go here.

    This is the CPU board before the modification. You can see the metal case with the encrypted CPU


    and here is the same board with the Z80 instead of the encrypted CPU and the unencrypted EPROMs installed