problem with galaga cocktail table machine. Please help!

[billygeg]

I have a problem with my galaga cocktail table machine. I purchased this unit off ebay about a year and a half ago and had nothing but problems with it! I probably only got about 24 hours use out of it before it started giving me problems. I emailed the guy I bought it from and he told me that judging by the error code on the screen I had to change one of the rams which he provided extra with the game. I changed the ram and I saw smoke and that was it! No monitor, No game, no nothing! I have messed with it a few time since and I got the game to work but without the screen. Recently I tried to turn it on again and all I hear is a constant ringing sound as if its not booting up. Is this a video card problem? A monitor problem? Both? can anybody help? I would really appreciate it! I love galaga since I'm a kid and its really tearing me up that I cannot play it..My name is bill..If you want to call me I live in NY and my number is (845) XXX-XXXX or I guess you can just email me.
Thanks alot
Bill

[SirPeale]

I edited the phone number out of your post.  Any and all replies should be here in this thread.  Posting your phone number on the 'net is asking for trouble.

When you replaced the RAM chip, did you make sure it was replaced the right way?  They only go the one way.

You're still getting nothing on the monitor?  Can you tell if the monitor is coming on?  Are the fuses blown, either on the monitor or in the cabinet?

[Lutus]

Please, for the love of all that is holy, check the fuses thoroughly.  I lost about seven hours when it was a blown fuse.  Ok, now down to business...

-Check that the solder job on your replacement part was not shorting to anything else, escpecially large solder blobs.

-Check the voltage output of the power supply with a multi-meter by checking the voltage input into the monitor and the gameboard PCB(s).

-While you are fixing things you may as well go ahead and do a capkit on the monitor if you haven't done so already.

-What monitor make and model do you have.

That should be a pretty good start.  If you can provide this information then we will be able to help you much more effectively.

Good luck.

PS:  Go ahead and unplug the power inputs to the monitor and the PCB while  you measure the voltage and leave them unplugged until the reliability of your power supply is checked. 

PSS:  And get those voltages ASAP for quick help.

[grantspain]

changing a chip will not cause a monitor fault,i think its likely to be what peale said

[twoloosenutz]

I HAVE TO ASK YOU WHEN YOU REPLACED THE CHIP DID YOU TAKE THE BOARD OUT! DID YOU MAKE A MASTAKE AND PLUG THE EDGE CONNECTER THE WRONG WAY . THIS CAN HAPPIN AND ESZY TO DO. IF YOU HAVE A BIG FUSE IN THE POWER SUPPLY IT MITE OF POPED THE VERT OUTPUT ON THE MONITOR. OR A SINK CHIP. WHERE DID THE SMOKE COME FROM DID YOU SEE IT. WITH A FLASH LIGHT LOOK GOOD ON THE BOARD TRY TO SEE IF YOU SEE A RESISTER BURNT OR A CHIP. TRY NOT TO PUT YOU FACE ON THE NECK BOARD IM IN NEW YORK TOO. I MAYBE ABLE TO HELP YOU!

[SirPeale]

And I have to ask that you not TYPE IN ALL CAPS, IT IS CONSIDERED SCREAMING.

[billygeg]

Hi All
I would like to thank all of you for your replies! I will check the output voltage on the power supply to make sure they are right. The monitor does have 1 fuse where the power comes into the board...The fuse center glass looks green in the middel so I figured it may have been blown. I did jump the fuse out but still nothing so I am assuming its good. Problem is I cannot check it for certain because its soldered onto the board of the monitor and I am very leary of messing with the monitor too much. I am a electrician and can solder and work on things like this to a extent but I am very scared of messing with the monitor too much...I heard it can give a pretty good Blast! If you guys can tell me how to discharge the capacitors it would be a great help. As for the monitor, Supposedly all the caps were replaced new just before I bought it. It could be the ram..I will get a bridge, take the old ram out, put the bridge in (which I should have done the first time) just incase this happens again and see what happens then. I will also get back with the numbers on the monitor and board... I do think this game was a put together! so I hope the monitor numbers and pcb numbers match what you guys are familiar with... Also I did notice that one chip on the video card near the monitor wire jack is in backwards in its bridge, Is it possible that this belongs backwards? I took all the chips out that were in bridges and cleaned them so I dont know if I put that one chip in backwards or if it was already like that and belongs that way...Ive never seen chips in backwards of how the board shows it supposed to be but I'm only a beginner. Again,  Thanks to all of you for your help!
Bill

[Lutus]

Jumped the fuse out???

I hope you mean that you desoldered the fuse and then tested it with a multimeter but I think you jumped the fuse with a wire.  I would definently say that this is a risky maneuver.  Most of the time it will be OK but for sure they are there for a reason.

EDIT: reread it, don't jump the fuse I guess is the key on the monitors

Also, there are numerous posts about discharging the monitor.  Once it is discharged and the anode cap is removed things are much less "shocking" I guess you could say.

[billygeg]

Nope! I mean I jumped the fuse out with a wire..I'm sure its not a great idea but once I did that the monitor came on with no picture at all...Just a dull white screen. I took the old ram out of the board and put a bridge in with a new ram...Still nothing! Any other suggestions? Like I said it was coming on and I was able to play it without the screen but suddenly it no longer boots up and I get a constant ringing sound. I always got the ringing sound even when it was working properly, but it would go away once the game went threw its self test and came on. The ringing would normally last about 5 seconds then i would hear the sound of my ship exploding and it came on ready to play. Now all I get is the constant ring tone.
Again, thanks guys!

[SirPeale]

Nope! I mean I jumped the fuse out with a wire.

BAD idea.  If you value it, replace it with the proper fuse.

[billygeg]

Hi again
I know! I know!...Its a very bad idea but I did it unfortunately. .The good news is when I did the screen came on but only in white. I pulled the whole power supply unit out and  tested it with my digital fluke meter. Its giving all the proper voltages so I think we can rule that out...I did happen to notice that I had a chip on the video card in backwards...I reversed it but NG! If anything it probably burned out.. Do you think this can be the culprit ? If so, how can I find a replacement chip? The board is two pieces. The video board is numbered DG-07-2 and is alittle smaller then the 2nd board. The second board is numbered DG-09-2....The chip that was in backwards is a 16 pin chip marked on the video board RM7 just next to the video plug connections..
Thanks for all your help!
Bill

[grantspain]

get the right fuse in there asap,chip in back to front means death to the chip but its hichly unlikely to affect anything else-replace the chip,its whats causing the problem(on that chip should be some id no. and make,what is it?)

[billygeg]

Hi, Thanks for the reply!
The chip doesnt have a name on it but it looks to have the texas instruments logo on it...The Letters and numbers are J310X   TBP18S030N and its a 16 pin chip.
Thanks!
Bill

[grantspain]

i just google'd that chip "TBP18S030N" and found plenty of places to get it,and i bet you a dollar bob roberts has got it

[billygeg]

Thanks for the response! I will definitely check his site and see if he has it and replace it. Do you think this would also be the cause of the game not starting? Also, where can I get the proper time delay fuses these monitors take? Can I get them on Bob Roberts site too?
Thanks!
Bill

[grantspain]

its seems logical that your fault stems from this chip,anti surge fuses can replace time delay-i think you should email bob roberts with your full requirements
there are some very quick fault findings methods i use that very quickly eliminate areas of a machine-it should take between 5 and 10 mins to prove what area the fault is in
with monitors the quick way is to turn the screen volts or brightness up,if you get a whiteish screen then barring a blanking problem the fault is on the power supply or game board
with power supplies meter all the outputs,if they are perfect then its down to the game board
obviously there are exceptions,but i ain't seen many in 20 years
trouble is getting you americans to listen to a brit

[billygeg]

LOL Grantspain! 
One more question! How do discharge the monitor? I want to pull it out to replace the fuse because it is soldered into the board but dont want to kill myself! I am a electrician and been shocked plenty of times by 110v...Its not the worst but I hear these machines and tv's pack a way larger punch!
Thanks!