Galaga crashes

Buddabing

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I hosted a baby shower tonight and I was entertaining the husbands upstairs. I turned on my Galaga which hasn't been on in a while, possibly months. After a while I came back and I noticed that the grid which briefly displays during POST was showing. I don't know if anyone had been playing the game. I turned the game off and back on and played a game and the game crashed after wave 8 or so.

I have a switcher and the Arcadeshop enhancement pack installed, if that matters.

Any ideas?
 
It might also be bad grounding and static buildup. I know that all 3 of my Bally/Midway games (and the Burgertime I used to have) freak out if youve been walking on carpet and touch a coin to something metal or discharge yourself on something. If thats the case, I am not sure about any sort of fixes, as it seems like its pretty common, granted I havent een one without it.
 
The problem is definitely voltage. The voltage reads 4.52 volts, I used the connection suggested by the Arcadeshop Galaga page, which is across a large capacitor on the main circuit board near a power connector.

I adjusted the trim pot on my switcher, but the voltage reading appeared to be the same regardless of the position of the pot. There is an indicator light on the switcher which reads green when the voltage is "in range" and it is green. It turns red when the pot is turned too far in either direction.

Not sure how to proceed from here.
 
so is it 4.5 on the board or off the switcher itself.??

you could swap in another switcher and see if its the switcher itself getting weak for whatever reason..

odd, the light stays green tho... thus my question where you are testing for the 4.5...

wonder if you can run +5 to +5 test points like on a PP board ? To distribute the power evenly rather than pushing it thru one point on the board?
 
I measured voltage at the switcher and the +5 volts reads 5.17, which is normal. It also adjusts.

Oddly enough the voltage on the board showed 4.95 volts today. ????

I measured voltage on the board according to Arcadeshop's recommendation, which is to measure it across a large capacitor located near the power connector.
 
Measure the voltage on the board at one of the chips. The adjust your switcher until the voltage on the board reads 5.20. That should take care of your resetting issue...
 
Could be an dirty Edge Connector. Try cleaning that. That could cause a drop in voltage.

The edge connector might need replacing as well if the fingers have lost their tension.
 
I reseated the connectors on the boards. No change.

I measured resistance between GND on the switcher to the minus terminal of the capacitor on the board. With the power off, the resistance was about an ohm. With the power on, about 200 ohms.

What should be used to clean edge connectors? An eraser, or alcohol+Qtip?
 
I looked at the edge connector, it didn't seem corroded or extra dirty. Neither does it seem loose. I cleaned it anyway with an eraser. When I was done I still got only 4.95 volts on the +5. The game still crashed but it got to the high twenties before doing so. I don't want to use too much elbow grease for fear of damaging the contacts.
 
I looked at the edge connector, it didn't seem corroded or extra dirty. Neither does it seem loose. I cleaned it anyway with an eraser. When I was done I still got only 4.95 volts on the +5. The game still crashed but it got to the high twenties before doing so. I don't want to use too much elbow grease for fear of damaging the contacts.

I already told you how to stop it from crashing....
 
I already told you how to stop it from crashing....

You'll get some losses through the connectors and wiring... measure the voltage at the cap and turn the voltage output of the power supply up to compensate for it like Mod was saying.

If that doesn't take care of it then you probably have some bad sockets or dirty chip legs causing issues. That's a common problem point on Galaga.
 
I already told you how to stop it from crashing....

I've already adjusted the switcher. The voltage on the switcher is adjustable and I measure it as 5.2 volts on the switcher. The voltage across a certain capacitor on the board measures 4.9 volts. I guess I can find another suitable point on the board to measure voltage, in case that particular cap is bad.

BTW the starfield doesn't move uniformly. It kind of stops and starts every once in a while. This doesn't affect gameplay. This has happened ever since I have owned the game. It doesn't happen in MAME but I think the starfield emulation in MAME is bogus. Is the starfield supposed to stop and start?
 
Are you saying you can't increase the voltage anymore? Is the knob turned up to the max on the switcher? If not increase it until you get 5.2V on the board. Check the voltage at several places on the board.
 
It sounds like to me that the connectors on the switcher may be kind of crappy. It only costs a few cents to put new connectors on the switcher for your +5vdc lug.
 
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