• [Article 6277]Omega Race (2) :: 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.

    omegarace_1603

     

    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…

    omegarace_1604 omegarace_1605

    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.

     



  • [Article 6270]Omega Race (2) :: 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.

    omegarace2_troubleshooting

    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 😀 😀 😀

    omegarace_1321

    so, PCB now is ok…

     

    What have I to do now?

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

     



  • [Article 6250]Omega Race (2) :: 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.

    omegarace_1319

    And then Kynar Wire!

    omegarace_1320

     

    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.

     



  • [Article 6237]Omega Race (2) :: PCB – part 1

    This was the PCB

    omegarace_1301So the acid made its job.

    The board had been socketed already

    omegarace_1302

    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

    omegarace_1305

    This is the board now

    …even if some tracks have gone

    omegarace_1309

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

     

     

     

     



  • [Article 6207]Omega Race (2) :: 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

    omegarace_0909

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

    and that’s all.



  • [Article 6128]Omega Race (2) :: 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

    omegarace_1021

    Same for the panel…

    omegarace_1023

    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.

    omegarace_0502

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

     

    omegarace_0506

    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

    omegarace_0409

    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.

    omegarace_0201

    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:
    omegarace_0103

    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

    Interno

    Esterno

    LEGNO Side art

    Parte frontale

    Parte superiore

    Parte posteriore fissa

    Back panel

    Fondo

    Altre parti (pannelli ecc.)

    Interni invisibili

    Interni visibili

    METALLO Control panel

    Viti in genere

    Coin door

    Cash door

    Serrature

    Interno della gettoniera

    Cash box

    Staffe e sostegni

    Altre parti in metallo

    PLASTICA / VETRO T-molding

    Control panel

    Marquee

    Vetro anteriore

    Specchio semiriflettente
    CARTA Instruction card

    Cardboard

    COMANDI Joy

    Pulsanti

    Altri comandi / FF

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

    Filtro di rete

    Fusibili

    CABLAGGIO “ALTE” TENSIONI Illuminazione

    Alimentazione TV

    CABLAGGIO BASSE TENSIONI Cab. basse tensioni

    Cab. altoparlanti

    Cab. video

    Cab. comandi

    ALIMENTAZIONE Trasformatori

    Schede di alimentazione

    TV Masse

    Elettronica

    Tubo

    AUDIO Altoparlanti

    Amplificatori

    GIOCO Scheda / Schede
    ALTRE PARTI Ruote

     

     

     



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

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

    superbug1501

    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

    superbug1502

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

    superbug1503

    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)

    superbug1504

    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.

    superbug1505

    Definitely better…

    Plugging the board I had this pattern

    superbug1506

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

    superbug1507

    .. 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

    defender_19in1_03

    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.

     

    defender_19in1_04

    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:

     

    defender_19in1_05

    fixed with some hot glue

     

    defender_19in1_06

     

    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.

    circus054

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

    circus055

    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:

    circus050

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

    circus051

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

    circus052

    Yes…

    Cutting all pins I could reach this status:

    circus053

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