Help with Galaga Boards

[RedlandMan]

someone correct me if im wrong but Galaga just like pacman run of ac voltage which that atx power supply is not giving you. I recently build a jamma adapter for pacman with Bob Roberts instructions ( gotta give him credit ) and you have to bridge some connections and apply power to another part that normanlly does not get power to bypass the diodes so you can put in the 5v dc which is what an atx power supply or a switcher would give you. The board usually transforms the voltage for you. Luis

 

[kb0jjn]

Yes I have found the sound pot and on every board I have teste I hear some sounds. Sometimes it is just white noise. One time it sounded like it was trying to boot up and then recycled. I pressed on the z80 chips and got a stady tone...Like something locked up. That was when I decided to change out all sockets.
The bootleg boards are going to wait. I want to get a good orignial set of galaga bords up and running. I will solder some more wires to the connector for the gnd.
I am currently looking at some 5 volt regulators to make a good power supply. I have several boat batteries in my radio room the computer power supply is not giving my the 5.15 volts this board needs.

 

[CrazyKongFan]

someone correct me if im wrong but Galaga just like pacman run of dc voltage which that atx power supply is not giving you. I recently build a jamma adapter for pacman with Bob Roberts instructions ( gotta give him credit ) and you have to bridge some connections and apply power to another part that normanlly does not get power to bypass the diodes so you can put in the 5v ac which is what an atx power supply or a switcher would give you. The board usually transforms the voltage for you. Luis

I think you mean AC, not DC, and no, Galaga doesn't use AC. It only uses +5VDC and +12VDC.

 

[Hypersport]

Did you measure the output of the Power supply before or after you hooked up the game board? The voltage may rise after you get the +5 on the 3 prong connector hooked up.

 

[kb0jjn]

That voltage was at the edge connector connected to the board. I am working on the connections to the 3 pin molex connector.
I should and probably will come off some funds for a good power supply. I have a bootleg board that has only 2 connectors. Edge connector and 3 or 4 pin connector. I will post a pic later. It also has a seperate board attached where the rom chips should be. It has about six chips and another socket for a rom I think.
The power supply with no load is only 4.88 volts and drops to 4.85 connected.
This particular board that I am working on had a tag on it indicating Dead board...Blank Screen. Since it had the old resistor packs and old sockets I went with the renue kit.

 

[kb0jjn]

I need an eprom programmer and if there are any suggestions on model or type, please let me know. I want to test my Roms and copy some with bad legs. It would be nice to test them with the romident and checksums.
I also have decided to scrap my computer power supply for a new one. Most every time I trouble shoot anything, I always check the power supply. Now it is time to take my own advice. Any suggestions on an good supply. From what I have read, switching supplies will not last as long.

 

[Alpha-tron]

The nice thing about arcade swtiching power supplies is that you can adjust the 5 volts side of the swtiching power suplly if you need to.
Compared to your typical computer power supply that you can not.

I hope this will answer your question about eprom burners..


http://forums.arcade-museum.com/showthread.php?t=171954&highlight=eprom+burner

 

[kb0jjn]

Will this one work even though it does NOT have the external power supply.
http://cgi.ebay.com/True-USB-GQ-4X-...757?pt=LH_DefaultDomain_2&hash=item43a7a40b85

 

[RedlandMan]

i have it and has worked for me so far. I just used a power supply i had laying around from a cordless phone

 

[kb0jjn]

here is the power supply I am going to get for the test bench.
http://cgi.ebay.com/330571172387?ru...id=m570.l2736&_nkw=330571172387&_fvi=1&_rdc=1

 

[kb0jjn]

I got one set working...I think...It plays blind.
While waiting on some parts I got bored and started probing some chips on another board. This particular board had the newer resistor packs and I.C. sockets. I noticed the sound kept repeting, about a 15-20 sec. loop, and many of the lines on z80a cpu were busy. Not much else going on any other z80. I changed the 54xx chip and cleaned all the other socked chips, that did nothing diffrent. I was about to call it a night when I finally decided to try one last thing, the dip switches. I looked up a web page I saved from Arcadeshop.com (Galaga information) and noticed on bank 6j pins 4 5 turned on. I switched them both off and almost right away I heard the "Boom". I was in shock and thought this can't be right you have to power down for the switch to take hold. Spent a bit more time with the dip switch settings an finally came up with 4 and 8 at 6k on and 4 on at 6j. Powered up and in about 10 seconds there is the "Boom" and about every 1:30 the attract mode sounds worked. I let that play while I went to house to lookup other pins. I attached a ground wire to a probe grounded K=credit L=stared game and M=fire. This was my first repair and it may have just been the dip switches all along. The tag on the board indicated garbage jumping on screen and strange sound from speaker.

 

[Alpha-tron]

Great news, All you need is a screen to make sure it's repaired.

You can now use it as a refernace board and repair the rest..

 

[CrazyKongFan]

Yeah, there's one dipswitch setting that just causes garbage on the screen. I was trying to set a friends PCB to TG settings, and thought I copied them all down right (I don't think I did it wrong) and the previously working PCB just showed garbage. I set it back to what I thought it had (using the dips at crazykong.com) and it still only showed garbage. There was one dip that wasn't labeled at crazykong.com, and that was the one causing the garbage.

 

[kb0jjn]

I think in this case the dip switch that caused this problem was 5 on bank 6j being set to on. I hope this helps someone other than me.
I relly would like to get a cabinet for the boards and get a game going.

 

[kb0jjn]

Yeah, there's one dipswitch setting that just causes garbage on the screen. I was trying to set a friends PCB to TG settings, and thought I copied them all down right (I don't think I did it wrong) and the previously working PCB just showed garbage. I set it back to what I thought it had (using the dips at crazykong.com) and it still only showed garbage. There was one dip that wasn't labeled at crazykong.com, and that was the one causing the garbage.

What was the dip switch and what did you set it too?

 

[CrazyKongFan]

I think it was SW7 on 6J, but I'm not 100% sure. SW7 isn't listed on crazykong.com, and TG's dipswitch settings for marathon (Rank D, extra ship at 20K/70K/every 70K) says "OFF/unused" for SW7.