Missile Command - ARII and PCB Questions

[Michael Roma]

Time for an update...

I had someone look at the board and it turned out that D7 had a couple of broken traces. They replaced the socket, fixed the traces and the game had HSYNC again.

I got the board back, put it in and powered it on. I could see the MISSILE COMMAND screen but it constantly reset. I pulled the Big Blue and put the old one back in to no avail. I power cycled the game several times and the HSYNC issue came back. I left the game powered on, resetting while I checked something and when I came back to the front the game was going thru its attract mode and looked normal. I played a few games and everything seemed fine. I power cycled the game and it started resetting again with HSYNC off.

I replaced the Big Blue with one from Bob Roberts as well as did a ARII repair kit (caps/resistor/transistors) but still have the same reset issue. Sometimes the HSYNC is off, other times it is not and I can see the MISSILE COMMAND title.

Voltages at the TPs on the main PCB are are +5.13V, +11.78V and -5.14V.

Also, my power brick does not have a normal looking (to me at least) bridge rectifier like other Atari power bricks I have seen (see below). I am assuming this PCB is its equivalent. Do these fail?

- Mike

 

[tb lilley]

That's not a power assembly for an MC upright. Is it the cabaret that you have? If so, then it probably is correct to the machine.

See this thread on Atari bridge rectifiers: http://forums.arcade-museum.com/showthread.php?t=133151

They can sometimes go wrong. If you have a known working big blue, the only other thing that might fail would be one of the two diodes. Might be worth checking those. There's nothing else on that rectifier board.

FWIW I suspect the power is ok and you probably need the MC PCB looking at again.

 

[bit_slicer]

I could see the MISSILE COMMAND screen but it constantly reset.

Almost sounds like a bad Pokey.

 

[Michael Roma]

I do not know what it is...

While I had the power brick out I cleaned up the fuses and fuse holders. I also pulled the Pokey and wiped the legs, and lightly cleaned the +5V contacts on the edge connector. Now the resets seem resolved but the game still comes up with HSYNC issues majority of the time. I have found that if I leave the game turned on, as-is with the funky HSYNC that it will correct itself after 10 minutes or so.

So what am I looking at? Board issues, power supply issue (ARII or brick)?

- Mike

 

[joeycuda]

Why would the hsync problem not be the monitor?

 

[Michael Roma]

I tested with another, known-working, monitor and get the same thing...

I did the same thing again today... Turned it on and it had the HYSNC problem, walked away for 5-10 min and when I came back it was working.

wierd...

- Mike

 

[Michael Roma]

Time for another (and hopefully final) update...

I put another monitor from a Centipede I just picked up and flipped into my MC. The HSync problem seems to be a thing of the past and the game is playing great.


- Mike