Space Invaders Marquee lights dim

Zinfer

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More of interest than searching for a fix. Is it common for the lights to dim with the thump-thump audio? The lights seem to keep pace with the beat. Just curious if that's a pretty common experience.
 
This should not be happening. The lights are their own speparate circuit. My guess....the lights/light sockets are dirty or getting loose. As the game "thumps", it cause minor vibration....causing the issue you're seeing.

These things work great for cleaning out the socket...
http://www.marcospecialties.com/product.asp?ic=77-SCS

Also, hit the sides and base of the bulb with some sandpaper
Edward
 
Oh and here I was thinking that was normal. I'm more inclined then to think that it's a weak power supply. I'll have to take a look at BR's power supply cap kits. It'd be nice to have more of a concensus though to see if the issue is more widespread than just a couple of us.
 
I'd be more than willing to bet its the power supply caps. The filter caps are supposed to keep the voltages stable, so when a load (such as the amp chip amplifying the THUMP) happens, the cap makes up for a slightly weakness. If the caps are old and can't handle it - you get these types of issues.

If you really crank up a car stereo, and carefully watch the display, most car stereos do the same thing too :)
 
I thought the lights were on the same circuit as the sound voltage? Anyway, my SI does the same thing on all 5 bulbs so it's not the sockets. I like the effect :)

This should not be happening. The lights are their own speparate circuit. My guess....the lights/light sockets are dirty or getting loose. As the game "thumps", it cause minor vibration....causing the issue you're seeing.

These things work great for cleaning out the socket...
http://www.marcospecialties.com/product.asp?ic=77-SCS

Also, hit the sides and base of the bulb with some sandpaper
Edward
 
Well, I can tell you all this.....it's not you power supplies. The lights are tapped straight off the transformer. It's AC juice. It never sees the power supply board.

Edward
 
So essentially, the correct answer would be - that's normal and they all do it.
 
hrm. I'll have to take a closer look apparently. If it's not the power supply and not the bulb sockets. There's not a whole lot else.
 
On mine it's not real obvious with the bezel on. The sound power does share the same circuit/fuse/transformer winding as the lights, at least before the power supply. Why can't the power supply be drawing enough juice on the thumps to drop the voltage getting to the lights? Maybe my transformer isn't putting enough voltage out on that winding to begin with?
 
Well, it's not something that is noticeable to anyone not paying attention. It's not a drastic voltage drop. It's just that if your standing right in front of it, at night, in a completely dark room with only the marquees lit in the arcade, and if you don't have tunnelvision with blasting aliens, using your perripheral vision, you can see a slight drop in the lamp brightness on each thump, especially when it gets down to like 6 invaders.
But maybe I'm just nitpicking.
 
More of interest than searching for a fix. Is it common for the lights to dim with the thump-thump audio? The lights seem to keep pace with the beat. Just curious if that's a pretty common experience.

Mine does the same thing, its definately a power issue. However game works fine so im not messing with it untill it gets worse or stops working all togther. on a sidenote my volums is cranked up so if i turned it down, i bet it wouldnt be as noticable.
 
Mine does the same thing, its definately a power issue. However game works fine so im not messing with it untill it gets worse or stops working all togther. on a sidenote my volums is cranked up so if i turned it down, i bet it wouldnt be as noticable.

Same deal with mine... my does the same thing, but it works fine and that's good enough for me.

... and how do you have your volume cranked up? Mines only about 1/4 of the way up and it's loud as all hell. You can hear the "thud" through the entire house.
 
Even if the lights are right off the transformer before the power supply, if they are sharing the same winding the power supply could still be spiking due to bad primary caps. If I do a bob roberts order in the near future I'll get a couple cap kits and do mine to see if it helps out.

Another idea - try cleaning the fuse or replacing the fuse holder!
 
It hadn't occurred to me about the cranked volume. I don't have it super loud, but it's about 'arcade' level.
 
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