Galaga Lines

[Bobby]

I have a Galaga game and its sick atm =[ any ideas on how to fix it here are some photos of it





-Bobby M.

[Spyridon]

First thing I would check is your power supply.  You can see how to test it here.

[Bobby]

I think it maybe the power supply it read 2.1volts I try to turn it up but it didn't go up that much just .2 or so

[Spyridon]

Sounds like you need to rebuild your power supply

[SirPeale]

Though possible, @ 2.1V you shouldn't be getting much of anything at all.  Where did you measure from?

[RayB]

Yeah that doesn't sound right. THe game would not even boot up with such low voltage.

[Pinball Wizard]

Looking at this: http://www.arcadeshop.com/galaga/galaga.htm  If you scroll down some you'll find some things about RAM. That looks similar to your problem.

[CheffoJeffo]

Though possible, @ 2.1V you shouldn't be getting much of anything at all.  Where did you measure from?

+1

Galaga is notorious for being thirsty and there is no way she would boot at 2.1V

[Bobby]

I just check it with a 2nd meter and it shows to be 5volts for the first 5mins of boot up its fine after 5mins the lines start to show up

[Kevin Mullins]

Could be heat related... I'd clean and re-seat any socketed chips. (ROM's, etc)
At the very least press them all in good.

[SirPeale]

Definitely thermal related issue.  Chip "creep" would explain a lot of that.  I'd definitely reseat any socketed chips.

[Bobby]

That was one of the first things i did when it went down took the rooms out and clean them and put them back in. is there any sites that may have them for sale?

[SirPeale]

If it comes up good at first, but gets bad as it's on, it's not a ROM problem.

Are there other socketed chips?  Reseat them too.

Could also be a cracked solder joint.  Starts off okay, but as it heats up it looses connection, causing the problems.

[Bobby]

Do you think it might have anything to do with the chassis board or is it on the game board the board looks fine.

[SirPeale]

That's definitely a board issue.

Just to be straight: the game STARTS okay, but after a few minutes turns into the photo with lines as seen above.  Is that correct?

[Bobby]

Yes Thats what it does. good for a few mins than turns into that.

[Zebidee]

Did you check the power supply voltages AFTER the lines start showing up?

[CheffoJeffo]

Do any of the chips get really hot after those few minutes ?

[channelmaniac]

Go to Fry's, Radio Shack, Maplins, etc... and pick up some component cooler spray.

If you can't find that then get a can of "air duster" spray and use it upside down so the liquid sprays out.

Cool off each of the 2147 RAM chips one at a time to see if the screen clears up when you freeze a particular chip. Replace that chip.

If it's not the 2147 RAM chips, there's a couple of chips that take the data from the motion RAM and adds in the other items such as scores/text. Check those. If that's not it then check the 74LS368 IC that buffers the clock on the video board. I've seen a bad one of those cause this issue too.

RJ