We all have our dreams. š I've decided to keep it simple (hopefully) and stick with 2 boards per cab. šI once had an dream of building two arcade towers. One for horizontal games and one for vertical. Like one rack with 10 slots for PCBs. Each slot with own power supply and so on) it turned out to be way to much work and could't find anybody to build the racks.
Common cause of jail bars?
- Thread starter big10p
- Start date
Funhouse71
Active member
Games have to be set per game one voltsge is not always good enough for another game, For instance if I set my +5v voltage for a single layer board this may not be good enough for a dual or triple layer board. Same goes for setting the voltage too high and installing a new PCB like my Pacman/Galaga 20th Anniversary PCB it causes sprite glitches as it likes to have a voltage somewhere like 4.75v to work properly.
Just dismantled the boardset to check everything is socketed correctly and to clean connectors.
So, are all the green trace wires a factory mod, then? Glue holding them in place looks pretty old. Also noticed a couple of ICs are piggy backed.
Also factory done, do you think?
So, are all the green trace wires a factory mod, then? Glue holding them in place looks pretty old. Also noticed a couple of ICs are piggy backed.
Also factory done, do you think?
Not likely a factory fit more a case of early essential upgrade or very professional repair a guy who worked with us in the 80s did added wires so neat you would have thought they were made that way but on converted scramble/Galaxian boards and often piggybacked the odd ic where required again unless unused pins were able to be allowed to float he would solder them all in placeā¦ I wish Iād time back then to sit and learn more from him! He had his own computer repair business too!
OMG, they're not soldered on.
What's best to do here? Solder them on or remove original ICs and fit sockets?
You mean power the game up with those chips off? I can try it, but won't they have been put there for a reason?
I know with faulty fujitus the internal connections to the legs fail. That's why piggybacking works on them. It possible this is what happened to the chips below the piggybacked ones but since they aren't fujutus the piggybacking could be for another reason.
That's why I asked since the best thing would be to remove the chips and put sockets in but that's a waste of time if the piggybacked chips aren't making a difference. Maybe accidentally left on during a fixing session?
That's why I asked since the best thing would be to remove the chips and put sockets in but that's a waste of time if the piggybacked chips aren't making a difference. Maybe accidentally left on during a fixing session?
Ah, I see. I'll try with them off and report back.
Thatās very odd?those chips which are piggy backed are multiplexers,which probably are tied to the data pins on those 6148 srams above,they might be the sprite buffer line rams.
the board set you have looks like a different revision to mine which Iām trying to repair,I will compare the boards.
the board set you have looks like a different revision to mine which Iām trying to repair,I will compare the boards.
Ok, the game seems to work the same with the piggyback chips removed. I played through several levels. I was having difficulty adding credits before which now seems easier, but that may be my imagination.
So, I guess I just leave the chips off, then?
So, I guess I just leave the chips off, then?
I've now fitted a high score save and freeplay mod, using the great Arcade ROM Patcher. All is working well with the increase in voltage having fixed the jailbar graphics issue. š
The only issue remaining are the small red and white lines on the left of the display. These are constantly changing causing a sort of speckle effect (see previous screenshot). They only appear when playing, but not in the title screen or demo. No big deal as they're off the play area, but it would be nice to find a fix.
The only issue remaining are the small red and white lines on the left of the display. These are constantly changing causing a sort of speckle effect (see previous screenshot). They only appear when playing, but not in the title screen or demo. No big deal as they're off the play area, but it would be nice to find a fix.