Missing Starfield, At first the starfield became erratic and eventually failed. Think I stuffed this one up meh live and learn.

Garbaled characters they were all lines except the ones that the above fixed however they were all still wrong. This also fixed some garbaled characters but they were all wrong!. I Found that EVERY single 74ls74 was bad except one at C4Įvery 74ls00 was bad also replacing them gave life to the board. Info taken from various sources from the net can't remember about the rom info, but the ram errors and pinouts were taken from Mikes Arcadeīlue Video Board (Spike) pic 1 white dots indicate IC's replaced interestingly enough some of which had red dots ) There is a small daugher card in a 28 pin socket at 4F.ĥD the game displays 'RAM OK' but you can't exit the setup pageĥC the game displays 'RAM OK', then reboot forever Makes everything nice,compact and neat.Ģ732-G5.4JF B7FF 2732 4J G5F Rapid Fire chip I find its a good idea to shorten the pins on the syncbus controller to make it sit just above the roms. The wire that is connected to the board from the regular Syncbus controller connects to a 74ls00 A2 pin 2 Good thing about these is there no wire that has to be connected to the board. You can use a Sync bus controller off pacman on these boards. I know the sound work as I used proms off a working board to test it.

Need the two missing Tri State proms(empty sockets) which have to do with sound. Syncbus controller had been put in the wrong way and as a result all chips except a 74ls02 were fried.įorgot to mention I knew the sync bus controller was stuffed and was using my pacman one to fix teh board. Board boots up then hangs at the ram ok rom ok screen and wont advance to the cross hatch.įix:Bad all the outputs at pins 1 through to 8 were High with no data flowing. Problem: Board boots up then hangs on RAM OKįix: common fault with these Gallags, bad boots up gets to the Ram ok, Rom ok, upright etc screen then resets.įix:Seems to be another common fault on these boards, stuck output pins 8 and 13.īad chips found after board fired output stuck low pin 13 Problem: Dead board.really really DEAD!.įix: bad and 7M Took ages to find but a got the board firing up. 2 CPUs one of which had red dot on it and both the Tri State Proms. Galaga (Code named Spike) Pic 2 Added some other amusing pics from the guy I bought this from who got it from a well known tech ), those who know the history of this board will know what im on about )Ĭhips found faulty via testing on working board were. Problem was another 74ls367 considering most of these chips were already in sockets towards the top I replaced them all to be safe. If you turn voltage right up board would run, turning it down again would stop on RAM OK.įix:This is where a Scope would have come in handy. Turned her on and she was alive with zeros all over the screen. Ok after many hours I replaced all the bad IC's and even had to pinch a few rare ones like the 74ls28 and stripped a stuffed pac board for the others IE 74ls259, 74ls368. 2 Z80s were bad but the rams were all ok even the 7489's. Using my little Ms Pacman board I tested the Z80's and rams. There were other IC's that appeared to be shorted but some of their pins were grounded already so I left them for now. When I found one I would then switch to the ground finger on the pcbs edge connector to make sure there was a short. The best and easiest way to locate all the effected chips was to one end of the multimeter on the +5 volt and test each pin on every IC. Going over the board I looked for anything that could cause a short so use my multimeter and did a continuity between the ground and +5 volt and there was a short to be sure. This board was a mess, when I first tried to fire it up nothing came up, I felt the top of the IC's and 2 were VERY hot so I quickly turned it off. I dont have the time in the day to be bother to check to see which layer is good and which one is bad, this board is prob best left for parts to get another galaga working.Įven in the picture in the listing I could see the CPU sync bus controller was tuned around the wrong way and sure enough when I got the board it was and all IC's on it had been completely fried.

QUOTE: 'this galaga board is untested, i doubt it very much it will work, i have had it in storage for a while so its a 99% it will not work other wise i would have used it long ago. This is the one I bought from E-bay it was listed as. I'll split the CPU and Video boards in separate posts. Only down side is they use common TTL chips to replace the custom ones of the original which makes them a BIG 2 layer board. They are quite popular because they have no custom chips, easy to reprogramed to the NAMCO or Midway set and are well made.

Love these boards to bits I've had 3 of them plus a alt board which I will post here I got off a mate.

Galaga rom 02