Recent content by jpx72

Bump!

Hello I am looking for a Sega MegaPlay PCB in working order, ideally from Europe, for a reasonable price. Thank you for your offer! Can provide feedback from various forums and eBay.

Yes Mame is my first choice but which rom? Any tips for that,?

Hello guys I have aquired an awesome slot cabinet with two monitors (one is touchscreen), which is controlled by a small factor PC with 1ghz cpu and 512mb ram. There is also an interface board plugged through usb ports which has 72 pin jamma-like connector to interface buttons, coin mech, lights...

Hello! Everything is perfect now! I solved the 368 mystery! It was a stupid thing - low power. The PC PSU I was using delivered too low power to the board with so many ICs. I switched to a standard arcade power supply with adjustable 5V and it works great now, I just pumped the voltage to 5,2V...

Anyone have some useful info for this Galaga bootleg? Everything on screen works flawlessly, just the starfield behavior is very weird. One time it scrolls down like it should and after a few seconds starts to dissapear and reappear again. Other time it just stands still and flicker. Sometimes...

All working , was only a mistake. Sorry.

Hello guys! I just returned to say that finally a friend of mine who knew what he was doing with an osciloscope was able to return this board back to life! The main problem weren't any bad components, only dirty/oxidised contacts. Cleaning wasn't enough, replacing Eprom sockets solved the...

Thank you very very much for your help, I have downloaded the schematic and will try to figure something out. Will update thread when I'm succesfull.

Thanks the Freeze button works as said. But the bad news is that although I have compared my dumps with the correct ones, foumd some discrepancies and reprogrammed the wrong eproms, I am still stuck on the same image (see video). So the problem is elsewhere, shame that I cannot use original...

Hmm I think I have the right roms now, but I would like to compare my dumps with a full set from a working board. Can't see anything on the input side wrong...

The credit system doesn't have any effect, or any dip switch in this row of switches. But when I switch all the switches on the second dip switch row ON, it locks on the test screen, the number at SOUND keeps changing randomly every second or two. Meanwhile you can change the credit system and...

Thanks I've inspected the whole board inside out but the only suspicious place seems the socketed D8255AC-5. The socket is from 2 pieces, so definitely not original, which can mean that this chip was exchanged for some reason. I will order a new one.

Hey thanks I have identified the 6 and 7th eprom, the 7th wasn't in the 0.184 mame galaga set, but I have found it in 0.37 galaga84.zip I have replaced the damaged eproms and now I hav some success. I know the pcb troubleshooting is not possible when you don't have the board in hands, but if...

For future reference I have done a bit of comparison of my dumped roms and galaga.zip from 0.184 mame set. My eproms may be damaged so the differences may be caused by this fact. #1 gg1_1b.3p #2 gg1_2b.3m #3 gg1_3.2m difference in 260 bytes #4 gg1_4b.2l #5 gg1_5b.3f difference in...