Requesting help with a non-booting Space Invaders cabaret

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Requesting help with a non-booting Space Invaders trimline

Hi all,

A few months back I purchased a non-working Space Invaders mini from a fellow KLOV'er here in Phoenix.

I finally have the time to give it some attention, and I could really use some help.

The machine starts up and begins making a series of 'chirp'-like noises. The screen warms up and displays what looks like an image with bad horizontal hold.

I've recorded a video of the startup loop and put it on YouTube:

http://youtu.be/PkkzKsECt2E

Any help or suggestions would be greatly appreciated! I have intermediate electronics know-how but no experience in repairing video games. So I could really use some guidance.

Thanks!
 
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Very interesting - thanks!

The SI makes 5 beeps each time, which corresponds to memory chip G12 according to that link.

I'll do some searching, but does anyone know of a source for those memory chips?
 
Thanks for the link. This is a Taito SI "trimline", and it has 3 perpendicular boards (pic attached).
 

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Here is a pic of the board w/ RAM, and the RAM itself.

Oddly, the manual I found online says the RAM is TMS4060NL for this model, but the chips in the pic are different. Possibly replaced at some point?
 

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There's a handful of crosses for that RAM chip (see my previous link). The ones you pictured are UPC411s.....same thing as the 4060, just made by a different manufacturer. From your picture....yours looks factory.

Edward
 
Great, thank you!

I'll order replacement RAM from that link and see if it does the trick.

I assume that people typically add sockets when performing this type of replacement? Seems like the sensible thing to do.
 
Great, thank you!

I'll order replacement RAM from that link and see if it does the trick.

I assume that people typically add sockets when performing this type of replacement? Seems like the sensible thing to do.

Yes, most do.....I would! Get some extra, you might have more than one. The test will stop at the first bad one, and reset itself. It will not advance until the bad one is replaced.

Edward
 
Just an FYI - those traces (at least on the Midway board) are pretty fragile so I usually clip the legs one at a time, remove the chip body and remove each pin and desolder the through holes before replacing with a good quality dual wipe socket. Cheap sockets will be an issue in the future so spend a little extra on quality sockets.

Greg

Great, thank you!

I'll order replacement RAM from that link and see if it does the trick.

I assume that people typically add sockets when performing this type of replacement? Seems like the sensible thing to do.
 
Thanks for the tip Greg.

What are you using to clip the legs? There's not much room to get to those, even with the board out.
 
What are you using to clip the legs? There's not much room to get to those, even with the board out.

I use these:
toolboxcutter_LRG.jpg
 
Say....

I seem to be missing some information.

The manual and schematics don't seem to have RAM chips numbered individually.

The Braze website indicates that "5 beeps" = location G12, but that doesn't seem to correspond to any labels I see.

I'll socket & replace them all eventually, but for troubleshooting purposes I want to replace #5 first.

Anyone know which chip is "G12"?
 
I agree - pretty much the same ones I use - same brand but an older pair. Beats damaging the board or buying a wave solder machine...

As for the location of the chip the location is in regard to the Midway boardset - there should be columns labeled on the board and rows numbered. Using a X,Y identification you can find the right one. If you have a Taito boardset I am not sure if the numbers match. I suppose if there is not a grid pattern and no way to identify which ones on the Taito boardset, since you make it all the way to the fifth one tested you could ground the output of one at a time until ICs for beeps 1-4 fail and create a pattern based on this. the test goes in sequence of the rows of RAM so you should be able to generate a known pattern by failing the first four. That make sense?
 
I definitely don't see anything suggesting column & row numbers. But there are small numbers appearing near each chip - and they're consistent with those displayed on the schematic from the Midway user guide.

The thing is the numbers start at the top left and go from 10 to 33. So that part doesn't correspond to anything like the G numbers mentioned in the Braze troubleshooting guide.
 
You could ground the output of one at a time until ICs for beeps 1-4 fail and create a pattern based on this. the test goes in sequence of the rows of RAM so you should be able to generate a known pattern by failing the first four. That make sense?

Yes, I think so. But to ask a potentially dumb question what should I be grounding those pins to? I sure don't want to mess up and ruin more of them.
 
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