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Showing content with the highest reputation on 29/11/22 in Posts

  1. Good news today. Before getting down about my Windy not working I thought best to go through some fundamental troubleshooting. I accessed the monitor area and simply reseated the neck board and all was well. I get an occasional momentary power interruption but I have a working machine. 😃
    4 points
  2. Hi all, this one took much more time than expected. First of all, this appears to be an early revision of this game's PCB All of the other boards I have are /1 instead of /0 However, first of all there were a few EPROMs and the CPU with broken pins: All could easily be fixed by soldering pins from spare ICs (I keep the bad EPROMs just for this reason). One of the EPROMs however had a pin broken almost at the case, that took some high temperature soldering work to be "fixed". All the EPROMs then have been dumped and a few of them needed erasing and re-programming, including the one with the problematic broken pin. However, this one gave a programming error twice even if it appeared to be erasing correctly. So that one was substituted with a spare TMS2708. I've also noticed that Q1,Q2,Q3 were missing, just the pins were left, so I've cleaned the holes and I decided I would install three replacement transistors only at the end of the repair, maybe this board couldn't be fixed after all. These transistor are only needed to actuate the counters in the cabinet by the way. Inspection of the solder side revealed a few "patches", the following picture shows only a few examples, but there were a few more: As the other Zaccaria PCBs of that era, the EPROM's sockets were the single contact kind, so I've just replaced them all, but initially I didn't think the 40 pins sockets needed replacement too, they were the "Red" kind, with this type of double-sided contacts: The board was also missing the Signetics 2621 sync generator, so I borrowed one from another PCB. The first power one, gave a completely black screen. This usually means no clock on these boards, so I proceeded to check both clock and reset pulse at the CPU pins. Of course the clock was missing but also the reset line was permanently high, and on a 2650 CPU this means permanently in the reset condition, so I decided to first address this issue. This is the peculiar reset pulse generator they have used and it puzzled me a bit initially. I couldn't understand how it would work at all unless what's labeled as CN7 pin 1 is connected to 5V, that would charge C2 with a small time constant, make the output of the first LS14's gate go low and turn off Q4 that makes also the second gate of the LS14 go low (which is the most complicated reset circuitry ever). Indeed I pulled one /1 board and that was the case, R88 was connected to 5V with a wired jumper, the other position of the jumper would bring it to CN7 pin 1. However, on the /0 PCB, there's no such jumper. I asked the owner of this board if he has anything going to CN7 on the cabinet's side and he confirmed there's nothing, so I just soldered a short wire from R88 to the nearest 5V trace and that brought back the reset pulse at power on. Now, the clock issue was just an intermittent socket connection on the 2621 sync generator, rocking the chip in the socket would make a picture appear on screen. I've then changed that socket too. At this point the board booted and hang on a completely drawn battlefield without alien formation and with the center part of the screen filled with random characters, actually every reset of the CPU would give a different result, like complete battlefield with aliens and frozen ship with random bullets moving on the screen. I've decided to run my diagnostic ROM and it would just confirm that all the various RAM segments were testing good and all ROMs checksum matched the correct values. Now, my diagnostic code isn't testing at all the three signetics 2636 PVIs, mostly because I haven't found any information on how to program them (the other option would be reading all the disassembled game code to figure it out...). So I thought I had intermittent PVIs sockets, the red ones I mentioned before, and changed all of them. This seemed to make the issue worse since now the game would just hang at the "GAME OVER" screen forever (notice that by changing the PVIs sockets I've likely swapped their position, but I didn't pay attention to that initially). I then thought I'd change also the last socket (the one for the CPU), and of course that didn't make any difference. Notice that while changing the PVI's sockets, I decided also to change one capacitor connected on the PVI's clock input that on this board was a large "tropical fish" 2.2nF one, soldered with untrimmed legs (so it was always neededing attention to have the legs away from other pins), all the other Galaxia boards have 100pF ceramic capacitors on that position, so I thought I'd stick with "what works" and used a 100pF ceramic on this one too. Now I had the right idea, what if one or two of the 2636 are faulty? This should be the first thing to check actually, since on the previous board I had two bad 2636 out of three, so I've tested them on a working board and indeed again two out of three were bad and would cause the "GAME OVER" screen forever or various graphic corruption issues. So, I've borrowed working 2636s from the other boards and the real repair nightmare of this board started. Now the attract mode seemed to work but you could see aliens randomly disappearing during a dive, or "teleport" in different spots of the screen randomly. Another issue was ship's shots would sometimes start from a different position different that the ship's top. This happened during a normal game too. Clearly this board is unplayable as it is. However all the rest seemed working fine, including all the game inputs. I thought the issue could be caused by the different romset this board has, compared to the two I repaired previously, but moving all the ROMs to another board would not show the issue, and also using the other romset on this board would still result in the weird diving aliens and bullet issues... I suspected this wasn't an issue with some failed ICs, but must have something to do with other board differences (and I couldn't find any real malfunction on the logic ICs no matter how hard I looked anyway). So I proceeded checking all the added jumpers, cut traces and parts against a working /1 board. One of the added capacitors on the solder side was on the Q output (pin 9) of 13B, mistakenly labeled as 12B on this part of the schematic, notice also that the capacitor isn't anywhere in the schematic that I could see. However, on the /1 board this capacitor is 330pF, while on the /0 was 1nF, so I've changed it to 330pF, and of course the problems remained identical as before. Then another difference was found around the "yellow wires" area. the mod was related to CKPVI signal, exactly the one connected to the first capacitor I've changed, the 2.2nF I've substituted with 100pF as per this schematic and confirmed on the working /1 boards. Now, CKPVI is actually the CKR signal of this schematic: On the /0 board I had however, CKPVI was actually CKR buffered by an otherwise unused LS08 AND gate, that's what the yellow wires do. However, in doing so, only CKPVI is affected by the capacitor delay and not all the rest of the ICs that get CKR as it is the case on /1 boards, so I've also reverted this mod, disconnected the AND buffer and jumpered the CKR line to the CKPVI (that was actually cut before adding the wires). Of course also this modification didn't solve the issue. At this point I was afraid it wasn't possible to diagnose the board correctly. However I reasoned that the issue was for sure on the 2636s since the diving objects and the ship's bullets are both handled by these ICs, so I've decided I would give a last look at the PVI's clock circuitry before giving up. Luckily I've noticed this other part of the circuit where they added yet another "timing" capacitor. A bit of background is needed: the Signetics 2650 has an asynchronous bus handshake, so it asserts an "opreq" pin at the start of R/W operations and waits for /OPACK to go low (this needs to be asserted by the peripherals) to end the bus cycle. This allows slow devices to be easily connected to the bus (but in later CPUs this was better accomplished by having a /WAIT input for example). Anyway, this part of the logic creates an immediate /OPACK to the cpu whenever it addresses anything that's not a PVI (the three CSPVIx are active high), or generates a slightly delayed /OPACK AFTER the actual /OPACK output of the PVIs goes low, this is accomplished by the 8C LS10 gate and the 10nF capacitor. Now, on /1 boards the capacitor is actually a 4.7nF one, and on the /0 board? Well, the capacitor was entirely missing!!! Can this explain all the weird behaviour? Let's find it out I thought. So I added the capacitor on the proper output of the 74LS10 to the nearest ground..... And... That did fix this board! WOW, I couldn't believe it really. I quite doubt this board did ever work properly before. I sincerely don't remember whether or not I've run all good 2636s on the old sockets to confirm the huge delay on CKPVI that was in place wouldn't really work to delay /OPACK enough. However, the board is working perfectly now, even during games I haven't seen any strange diving alien issue or bullet one. I believe it's now practically a /1 in all but cosmetic aspects. I doubt anyone will run in another /0 Zaccaria Galaxia PCB, but I thought I'd share the fix anyway. Frank IZ8DWF
    3 points
  3. I picked up a 2931 tube/chassis from the @namastepat stash recently to transplant into my Blast which is exhibiting issues and it’s an absolutely stunning example. Given what 2931 chassis alone sell for in “Russian Roulette” condition from China, alongside the shipping and fees; a tube / chassis combo at this price from a trusted arcade hobbyist in Oz is a steal. The attention to detail and patience during the sale was much appreciated and I highly recommend this seller for those on the fence. A+ and GLWTS.
    3 points
  4. That Shit right there is what this site is all about I am impressed with the dedication Aussie Arcade Home of the backyarder
    2 points
  5. Next mission, bit of a disaster when attempting to adjust purity … Ring assembly pretty much fell apart. A few chunks fell off it when doing an initial convergence tweak, I thought nothing of it. When it came to resetting the yoke, as I was pulling the ring assembly away it pretty much just fell apart 🤷‍♂️ Searched my 51cm spare CRTs , all unfortunately have a thin neck, so thier assemblies wouldn’t work….. Time to replicate Reproduction of the ring assembly from two different diameter PVC pipes from Bunnings to match neck thickness and outer ring diameter all from PVC. Thickness matched to original crumbled mess. Inside lined with 2 layers of heavy duty cloth tape I’m afraid of this thin PVC melting. See what happens. 🤷‍♂️ PVC cylinder “body” is frightfully thin. Painstakingly dremeled out with a stone grinder attachment. In between pvc “discs” that help the rings move smoothly when adjusting. Again cut from PVC and very slowly dremeled with stone grinder attachment to make nearly paper thin. Two larger discs as you can see on either end, closest to the yoke is epoxied, to stop everything coming forward. Disc closest to the clamp is snug but moveable to allow adjustment, once done can be shifted up against the rings, while the clamp stops everything moving. Quite a mission. Was placed on the neck and tightened, and the cabinet let run for 2 hours. Got warm but nothing is melting. Rings are affecting picture as they should. Will have to do for now…. Probably the most bonkers thing I’ve created 😂
    2 points
  6. Ow sweet, you pair made up now?. Cool, now on with the show. We have a forum to entertain.
    1 point
  7. In thinking about that, I don't believe you were involved with that witch hunt, And if I came off a bit defensive earlier...I do apologize.
    1 point
  8. Going forward this will start to go faster, and faster, But at this point the machine just kind of starts to builds itself now all the math is correct, and we have the physical hard copy...The marquee art is giving me a problem and we shall go into that in more detail... Oh before we go there, I forgot the side art plane pic, that wasn't easy to do even though it looks simple, it is actually a two dimensional representation of a 3 dimensional image...Just saying... But we may not use all of it, still deciding, beings it is a vector we can make it any size we want and may zoom in on just part of it as big.
    1 point
  9. Oh and we can't forget about welding the wing struts, We have more of this to do and probably should cover that a little deeper But anyway thats me JENNIFER!...That was a fun day, my girlfriend totally ran away after taking the pic screaming how she went blind, and tripped over a bucket, I still got to laugh.
    1 point
  10. Hmmmm? Sorry, was just reading this thread here. http://forum.arcadecontrols.com/index.php/topic,163889.160.html Thanks for the heads up. It's hard to tell what's happening because you deleted all your posts, but it does get juicy around page 5 🍻
    1 point
  11. Thank you Evan, that puts my mind at ease. 🙂
    1 point
  12. Hi @creech77 Sorry for the late reply, I will follow the MGL37 rules of "Also letting you all know you cannot milk the gorilla in this game for continued points. (the leeching of the gorilla. Especially Level 1)."
    1 point
  13. Good read Forums are for this sort of thing Someone in the world will repair one in the future and now your repair log is available even if it just hints at a repair aid for them all they need to do is a web search
    1 point
  14. Thanks for the kind words @djsheep Happy to help out another local candy collector.
    1 point
  15. John! I thought you might find this interesting mate, I recalled what you did for @gsuttorwhich was part of the inspiration , apart from 3d printing (which I don’t particularly have access to or clever enough to create that way) I thought I’d try to replicate. Hoping it lasts mate, seems to do it’s job, was quite a task to make I’d rather not have to repeat though 😂
    1 point
  16. Outsider! Edit: hang on, that was me I had in mind!
    1 point
  17. Hi, it looks great, just like a bought one! These old CRT convergence assemblies are becoming very fragile with age - I encountered a similar issue a while back and ended up making a 3D printed replacement for that one. Luckily the magnetic rings were intact in this instance as well otherwise it would have been a lost cause. Coming together nicely, keep up the great work! Regards, John.
    1 point
  18. Pessimeister: 313, 400 I'm using keyboard - left hand WASD for movement and the right IJKL for shooting direction. I haven't tried directional arrows funnily enough - might be smoother. My left pointer finger is a bit sore today. I think I know why. 🙂 This game is full on!
    1 point
  19. Sounds like you're looking in the right places (plus Gumtree and if you like gambling Lloyds). Just have to be lucky and possibly accept that by 30 years old most cabs are starting to show their age and might need a bit of tinkering. Might also be worth working out what you want to play (and how) and work backwards (original hardware, emulation, CRT etc). Like if your whole aim is to play SF2:WW on original hardware a Game Wizard might be a little unrewarding.
    1 point
  20. Coaxed the boss into having our little XMAS party as the 1989 Retro Arcade Bar in Newtown Sydney - nice to go to a place with proper arcade games!
    1 point
  21. I don't own a candy cabinet but have been looking for a nice candy cabinet for a few years now. It is the reason I joined this site, this is my experience; I've always wanted an Egret II or an Astro City. I'd probably want to pay 1 - 2k delivered to Melbourne for a very nice and tidy Astro City or 2.5 - 3.5k (maybe higher to be realistic) for a nice Egret II like the one above. I have seen a few Astros come up over the last few years and they seem to go quickly and I am always a bit hesitant as my preference is definitely the Egret II and I want it cosmetically clean as it will sit in my living room. I have never seen an Egret II offered for sale but fully expect someone will blow any offer I make out of the water if one comes up. I have seen two Atomiswaves in the time i have been looking. One was on FB marketplace for a matter of minutes before it was sold, $1200 was the asking price from memory. Another for 2.5kish i think which I was really tempted for and was surprised it was for sale for a while (possibly the one mentioned above) The release of the Astro City and Egret II Mini Consoles really messed up my Ebay and Gumtree alerts. The Game Wizard Extreme looks interesting too, the one that looks like a Vewlix, especially as I have a large schmup library on my Switch. I am thinking that could be an option for me as I have no experience with dealing with aging 90s tech and electrical stuff. I would be interested in opinions on that thing, though it is expensive. Actually just got back from Japan yesterday, my favourite arcade seems to be quite busy most days I went. Below is a picture. Its empty as it was 10am. This day was the morning I arrived, I dropped my luggage off, caught a train to Akihabara at 10am and played on machines until I could check in at 3pm haha. Any offers of cabs for sale or any tips on where or how I should be looking would be much appreciated.
    1 point
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