Star Trek vector game got cranky.

jkoolpe

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Hey all!

Well, I had my Halloween party and it was another fun-filled success (I'll be posting pictures shortly on the main arcade board), but as it apt to happen, I did have a game failure.

My Star Trek developed an annoying problem...I turn it on and it boots up fine, but within 10-15 seconds, the screen goes dark and sometimes it also emits pure static for sound. Sometimes it switches to Space Fury, too (I have Clay's multikit installed), but usually it just goes dark. The marquee is still lit, but the game does not play blind so I know it's not the infamous G08 monitor :D .

I only had time to try to reseat the main cage board, but that didn't solve the problem...didn't have time to do anything else last night as there was a ton of folks enjoying the games :) .

I'm thinking that the power supply is unhappy? I bought replacement caps awhile back, but never installed them. I was a little worried when I got the new caps as they have the same ratings as the originals, but they are significantly smaller in size than the originals. Does that matter at all? I'll also shore up the solder at the connectors when I pull out the PS (when I get a chance), and reseat connectors and chips.

Any other ideas/clues? Anyone else have a similar issue?

Thanks for any help in advance, as always!

Jon
 
Jon,

Check your voltages in the cage and then remove Clay's kit to simplify the debugging. I can send you a set of boards if you need a reference.
 
My dedicated Star Trek: SOS upright was exhibiting similar issues, but instead of the monitor going dark the game would just lock up or reboot itself. These problems started happening on their own 5-10 seconds after power up, or when you tried to coin up.

A friend of mine fixed it. There was a burned pin on one of two headers on the power supply, and the corresponding Molex connector on the wiring harness was also burned. After a power supply rebuild (replaced the burned header, and replaced all the caps while he had the board out of the PS cage) and replacement of the burned connector on the harness along with all of the individual pins in order to get a get solid connection, voltages were tested and adjusted and it fired up on the first try.

I wouldn't power up your game any more until you can verify that your power supply and harness connectors are good and the voltages are correct. I was told by my tech friend, "It looks like the G80 power supply has a tendency to overpower the 5vdc (logic) line and destroy the game boards." You can install a switcher in place of the 5vdc in order to avoid this possibility. In my case we just overhauled the power supply and replaced the Molex connector on the harness and all of the pins in it so the connections were good. My game runs perfectly now on a rock solid +5 volts.

Newer caps being a lot smaller than the originals despite identical ratings... not a problem and that is often the case. I suspect it is because over the last 30 years the industry has come up with better electrolytic formulas that can hold greater charges more efficiently, and that allows the caps to be physically smaller.
 
Thanks guys.

I actually have an extra complete boardset...I haven't fully tested it, but the cards that I did test a couple of years back worked fine...I remember the sound board produced very low sound, but I fixed that by replacing the caps on it.

I will pull the PS when I get a chance and replace the caps and see if the connector needs replacing...probably won't get to it until at least this weekend, though...

I'll let y'all know :) ...

Jon
 
Yea, get right to work on those pesky power issues!

He's lucky to have a friend like you to supply a spare set of boards as a reference! Sure would make the debugging easier.
 
Update:

Well, I finally had some time this week and here's what I did...

I completely rebuilt the G80 power supply...new caps, diodes, transistors, voltage regulators...the works. Reflowed solder to every connector of course, too...

Pulled each board from the cage, reseated chips where I could, and also cleaned up the interboard connector in the back of the cage.

Plugged it all back in, put everything back together, and...wait for it... :D ...



It seems to be OK now...I played a few games and left it out for awhile and no failure!

I'm keeping my fingers crossed, but all looks good!

Thanks for everyone's input...

Jon
 
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