Star Trek : Strategic Operations Simulator - infinite loop at game start

[MadocOwain]

I powered on my cockpit Star Trek SOS today, everything came up bright and beautiful. I pressed Start, got the "Welcome aboard, Captain" and all normal graphics and sounds as it spawned the starting objects but when it got to the Starbase, it then spawned another Starbase (with sound!), then another, and another, and another. I turned it off after 7. Turned it back on, same deal. I pulled the boards and pressed on the socketed chips, put it back together, same thing. This seems like a really, really weird issue, any ideas what could be causing this and how to make it go? /Pakled

 

[MadocOwain]

See the video:

 

[MadocOwain]

Voltages at the PS for +5v is 5.11 .. turned up to 5.4 and down to 5.0 and restarted without effect.

 

[demogo]

That sounds like a great feature! You'll do really, really well scorewise in that game!

 

[mecha]

there's an issue that emerges with those power supplies, I believe it pertains to not enough ground wire connections which results in scorching plugs. this will result in voltage drops. I'm sure there's some guide somewhere that shows how to fix this. the only SOS I worked on I was tasked with fixing something on the G08. the game part worked fine and monitor mods were already done. I know of a place that rather than fixing said power supply faults, they just keep having the G08 fixed about 40 times because it gets bad enough the game doesn't boot and G08s lack protections 6100s have if there's no XY signal going in.

 

[VectorCollector]

Do you have a standard boardset/cage installed or the VL multi installed?
Do you have "extra" spare PCBs to narrow down the bad board? Which is probably the CPU. And likely a TTL issue.

@BackInTime82

 

[alfonzotan]

 

[VectorCollector]

KLOV KHANSENSUS ->

 

[Arcadium]

I'll take a WAG and say it's one of the 2114 RAM chips (U26 - U29) on the CPU board. Try swapping the positions of all four and see if this error goes away and shows up as something else. Worth a shot.

 

[MadocOwain]

Do you have a standard boardset/cage installed or the VL multi installed?
Do you have "extra" spare PCBs to narrow down the bad board? Which is probably the CPU. And likely a TTL issue.

@BackInTime82

So far as I can tell it's all original parts, except for the free play chip(?, I'd have to look again but I think this game has it), and the Peter Chou switching PS.

 

[VectorCollector]

I'll take a WAG and say it's one of the 2114 RAM chips (U26 - U29) on the CPU board. Try swapping the positions of all four and see if this error goes away and shows up as something else. Worth a shot.

 

[BackInTime82]

Do you have a standard boardset/cage installed or the VL multi installed?
Do you have "extra" spare PCBs to narrow down the bad board? Which is probably the CPU. And likely a TTL issue.

@BackInTime82

I'm helping him via a local Facebook page. Methinks it's an EPROM issue. But don't speculate. Approach the problem systematically and use the built in self test to rule out all the really easy stuff. Can't say I've ever seen this behavior despite it being really cool.

 

[ArcadeTechGW]

So, what does the Self Test show when you turn it on?

 

[VectorCollector]

I'm helping him via a local Facebook page. Methinks it's an EPROM issue. But don't speculate. Approach the problem systematically and use the built in self test to rule out all the really easy stuff. Can't say I've ever seen this behavior despite it being really cool.

Wile E suggested RAM.
Did he burn the xydiag ROM and try that?

Sega XY Diagnostic ROM v1.0

After a recent tube swap, my G08 needed some serious work on the purity and convergence. Unfortunately Sega's self-test doesn't include any test patterns really suitable for making those adjustments. This was all the motivation I needed to code up a new ROM for the CPU board that displays a...

forums.arcade-museum.com

 

[BackInTime82]

Wile E suggested RAM.
Did he burn the xydiag ROM and try that?

Sega XY Diagnostic ROM v1.0

After a recent tube swap, my G08 needed some serious work on the purity and convergence. Unfortunately Sega's self-test doesn't include any test patterns really suitable for making those adjustments. This was all the motivation I needed to code up a new ROM for the CPU board that displays a...

forums.arcade-museum.com

Anything is possible. My gut says it's an EPROM issue which the built in self test will identify right away. If everything there passes then yes, you need to be a little more invasive. I always test all my RAM in a handheld tester and I rarely encounter RAM addressing problems on the CPU board. But the diagnostic ROM will check all of that easily if you don't have the separate test gear. In my experience, a bad program RAM on the CPU card will result in a halted game (no boot) or some other really strange and erratic behavior far from normal rather than a game that seems to work perfectly with the exception of the star base counter.

 

[bman7418]

that's a ram, or counter issue

 

[MadocOwain]

BackInTime82 took a look at the boards with me last night. It turned out to be the security chip on the CPU board causing the issue. Once the chip was replaced with another known good specimen, it worked properly. Thanks a million!!

 

[demogo]

BackInTime82 took a look at the boards with me last night. It turned out to be the security chip on the CPU board causing the issue. Once the chip was replaced with another known good specimen, it worked properly. Thanks a million!!

How fortunate that you live in Indiana!