Please help bring Galaga to life.

mitchschaft

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I speant the better part of 8 hours removing chips, cleaning and replacing legs today. It was a lot of fun and a learning experience.

When I power it up, the screen is blank but powers on, the speaker makes clicking noises or no noises.

I get 5 volts to the CPU and video PCB. It has the original, linear power supply.

Other than that, I am not sure where to go. I've tried using the troubleshooting steps from here, but they don't say much in the way of a dead system: http://www.arcadeshop.com/galaga/galaga.htm

I have an o-scope and a multimeter at my disposal. This is also my first restore attempt and I'm pretty excited.
 

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Experts, am I missing a chip here? Would this be the root of my troubles?
 

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I'll have to check mine at home, all the ones I am seeing on the net look different than yours. Nice Howard app on the phone. Miss baby gorilla.
 
Could be.
There should be a "00XX" Namco custom IC there.
According to the arcadeshop webpage, it's an "address multiplexer" of some sort.
Sounds kinda important to me, but I don't know for sure what symtom a working PCB exhibits when it is missing.
 
Ok, can't believe I missed it before. Here are a couple pics of each board. It's an original and not a copy as far as I know. If it's a chip I can order and don't have to burn I'll go ahead and do that asap.
 

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Your board looks authentic (not bootleg) to me. It should have "Midway" printed on it somewhere.

The Namco 00xx custom isn't a "programmable" chip. And unfortunately it also isn't common, nor in production. They're actually kinda hard to find, which is probably why yours got robbed at some point. Bob Roberts may have a stash and sell some; email him and ask. JROK has designed some replacements for some of the Namco custom ICs, but I don't know if the 00xx is among those he's done: http://www.jrok.com/project/custom_ic/gal_replace.jpg

You might post a WTB ad, or maybe some regular reader of this forum might have one to sell you... Good luck in your hunt!
 
Thanks, man. If it's too expensive, I might as well throw down cash for a working board from a member here. I bought this cheap as non-working to learn how to fix myself.
 
Bob doesn't have any, but he told me to find a broken DigDug board to get that chip off of to go any further. I'm on the hunt, guys! Hope they're cheap.
 
I didn't mean to imply that your board was not original, sorry if it came across that way. I was just searching all the pictures I could and didn't find the second board set that you were working on. Hope you find that chip you need.
 
those different xxxx chips are found on a lot of boards. i stole a couple for my pole position last time. dig dug isn't the only one.
 
Cool, thanks, guys. I have a couple options lined up and may end up going with that new chip if I can't get a DigDug cheap enough.

Does anyone want to school me on using an oscope? It's a 350MHz Tektronix and I'm looking for an excuse to play around with it. What are some chips I can probe and what should my settings be at besides 10x?
 
http://www.youtube.com/user/randyfromm#p/u/76/RJT-uSSWVJ4

There are half a dozen more chapters in that series on his YouTube channel.

Probably 1 or 2 V/div on the vertical scale, a microsecond/div give or take a few clicks on the horizontal (time) scale. Start by looking at the ground and power rails (should be pretty boring... straight lines). Hopefully you don't see ripple on your +5V (you'd need to slow down the time scale quite a bit to look for it). Then (with the horiz speed cranked up again) start by looking at the clock pulses. Then maybe probe R/W lines or address/data lines. These last ones aren't periodic, so they won't trigger and look steady like a clock signal will, but you'll be able to see pulses to indicate digital activity.

Be careful not to short adjacent IC legs with your probe!
 
Alright, my Dug Dug board came in and I threw the 00xx chip in Galaga. I also got my monitor working so I can see what's going on. Check out the pics.

Where would you guys go from here?
 

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Most likely it was not the missing chip that was causing this problem.
I think it had this issue before and someone robbed a part off your mother board to fix another machine. So even tho you installed another chip it might still have the same problem as before.
 
My galaga had a double row of socket on the board. Now this wasn't my fix but I think it was someone fix to deal with a loose sockets.
 

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