Ok i need some help please with a pcb i brought westlefest. it has a very odd mod or fix mounted on the top of the pcb.im not sure what it dose but the screen is a bit pinkish and the red and blue can be ajusted on the supergun/arcade cab but not the green it dose nothing.
Looks like a RGB boost amplifier. Edit: Which indeed are the cause of your problem. If you remove it and re-do the original connections for your system board, it should work fine (unless the board itself has a faulty output on one of it's colors) Btw... Beautiful wiring on the JAMMA connector
hi need some help the other day i brought 3 untested pcb's all of them where working ok 100% until the other day. i was useing the game in the cab then this happend any help would be great. the game was working fine no probs i have been useing other pcb's in the cab ok so i dont think that is the problame.
if you look carefully to the picture, you will see that the game characters are fine and just the background is messed. Usually, repeated tiles mean address errors on the graphics ROM. That's a Konami game, not ? If so it has a lot of surface mounted chips and it's possible that a leg in one of them has disconnected of the board. You can test this by gently applying pressure to the big chips of the board and observe if the graphics change. If you see that this is indeed the problem and you're unable to "refresh" the solders I advice you to search for someone capable of such soldering. Also address errors can happen if the ROM chips are placed on sockets and those are dirty or oxidized. Finally, oxidized copper tracks might cause communications within the board to fail. Again, touching the board is a possible way to detect disconnected address or data lines as your finger induces 60hz (or 50hz if you're in Europe) in the board if lines are disconnected.
rod_wod sent me pics of the board in question through PM. An Konami GX068 with the Asterix game. For documentation I decided to post this on the thread, as well. Some people using search may find this information useful in the future: It's quite regrettable it failed. It looks so mint... Considering it's in such great physical shape it may have a blown chip. All the ROMs are soldered straight to the board, also which puts my bad connections theory down. Four possibilities are: Bad graphics RAM (the ram which stores the numbers of the tiles that will show on the screen) Bad graphic address bus buffers (these chips interface the ROM bus which has several ROM chips connected in parallel so the big square LSI chips don't get too much current drained from them.) Bad tracks on the mother board. One or more pins loose on the QFP (square chips with large ammount of pins) KONAMI LSIs. I'd suggest you ask someone who can repair vintage computer boards have a look at it. Or better, someone who can repair arcade boards. Now, as an extra, a quick and dirty explanation on the repetition of tiles shown on the posted picture: Early arcade games work by fetching graphic patterns from huge banks of ROM chips and mapping them in squares which are called "tiles". Instead of using raster bitmaps like modern systems. The tiles system is not very flexible as it does not allow for changes of the graphical data making it not suitable for programmable multi purpose devices such as video games or personal computers. Since arcade boards will run the same program through their entire service life, such a tiles based system not only provides ease of programming but it also enhances the graphical performance greatly as each "block" of the screen memory is just a position on a "name table memory" which in turns tell the graphics hardware which tile fetch from the ROM array to draw at that screen "slot" or "block". And then, the analysis of the repetition pattern of tiles can be used to diagnosis the exact location of the fault if the person doing the repair has full understanding of how the specific graphics hardware system being serviced works. Unfortunately I can't give you a "do this" or "do that" pointer as I don't know the said hardware (GX068) myself. If you have more questions, let me know. :thumbsup:
The proper tools for such a repair would be an oscilloscope, logic probe or both. Along with some knowledge of how the board itself work.
Well thats that then its a real shame cos it was working fine the shock of it being turned on busted it. i will look into this oscilloscope cheers for all your help l_oliveira all the best.
If you feel it's worth fixing then there are a few people who are willing (at cost) to check these PCBs out. At the very least they could establish the source of fault and then obtain a quote for fixing it. Normally you are required to pay a deposit. It might be cheaper to locate a new board, but I don't know this board at all or whether it's easy to repair / find spares for. Try on Jamma+ and post in the repairs section.
Oscilloscopes aren't cheap - and yes, the best tool is knowledge. I'd say I'd take a look, but I've got so much on at the moment, I don't think I'd be able to get around to it any time soon.
crappy fish Hello and welcome to another naff pcb well this one is the happy fish 195 or as i like to call it the crappy fish (pic below) i think i have had a similar problem before with another bootleg pcb but that had a dodgy chip on it. -so dose my cab not like these things -or is this just a naff pcb -is their anyone else who has had this problem. ps i would just like to say that i prefer real pcbs but i was thinking of saving some cash and space + this has loads of cool games on it that can be hard to find..:thumbsup:
hi really other pcb's work fine how do i do this here is a pic of my jamma conecter and this is what they sent me mine http://img37.imagefra.me/img/img37/7...dm_aaae76f.jpg pics they sent me http://img37.imagefra.me/img/img37/7...bm_a046061.jpg http://img38.imagefra.me/img/img38/7...cm_0dfae58.jpg i seem to have more leads pluged in then they have i'm clueless
Try a flying lead from video ground (pin 14, counting from the left) to ground (pin 1 or 2), as the screen image is basically what happens when you do not have ground connected and you notice that you do not have anything connected to pin 14.
super trio video problame ok hello everyone ..first i have to say sorry to anyone who is sick of my jamma video problem's.. this is super trio brought from a reliable seller the game runs ok with sound and the buttons work you can see the game moving but the only picture i get is this one below. the lines are static and not moving up and down like with the problem i had the other day with my ground pin not being connected.i'm thinking i should re do my pin out but i don't know why its like this in the first place. any help please
