Silicon Gaming Odyssey Slot Machine

[Jawbreaker]

Hello,

I just picked up a used Odyssey and am trying to work through a few issues.

The main one being the fact that the video will give a perfect picture for a second or two, and then gets streaks of random color vertically on the screen. It almost seems like when the music stops, the picture resumes fine for a second or two. I plugged in a computer monitor to the video card output, and get the same bad image on the external monitor - so I'm thinking it may be the video card.

Also, I noticed that the cards were not plugged in their proper place. I have a Tucson MB in the machine and the order should be (L-R) Phsyco, video, SCSI, Empty. It was set up (L-R) Pshyco, SCSI, Video, Empty. Which doesn't match up with either the Tucson or the Thor config.

I swapped the cards to put them in their proper order, but I still get the video noise. Also on boot up - there are streaks of blue and white video noise on the screen. Then the Odyssey logo comes up perfectly...the game menu loads and looks perfect for a couple of seconds - until the music starts and then it goes nuts. I unplugged the audio amp plugs (both power and input) to see if it was inducing noise into the video - but it didn't help.

Also the audio sounds terrible, like either the speakers are blown, or the amp is bad. I plan on replacing the major components on the amp card to see if the sound improves after I solve the video issues.

Lastly, when I got the machine (which was shipped cross country) I couldn't get it to boot. After some investigating, I found the switch on the front of my Pshyco board must have got moved during shipping. It supposed to be up (P) but it was down. There was bubble wrap packed around the cards - so it probably just got bumped.

If indeed it is a video card - are these comonly available? Are the the same ones in older computers or are they specific to the Odyssey. I know LA Slots has them, but won't ship to me since I'm in WI.

Thanks for any help.

**Added information - I noticed when I go to a help menu, where there is a non-moving video picture, the image is fine. Also when "Out to Lunch" appears the video is fine. It only goes crazy when there is some sort of animation on the screen (which is most of the time). I also determined the speakers are fine, but the audio amp is bad. If I plug headphones into the computer output the music sounds great. If I go through the amp, with a new speaker - it is garbled. I ordered new caps and a new amplifier chip from digikey.

I found several Diamond Stealth 64 video cards on ebay, some with the part numbers extemely close, but no perfect matches. I bought one for $4 to see if it works. I also experimented with removing the piggyback memory expansion on the video card, but then I get no video at all.

-Tim

[Jawbreaker]

I ended up fixing the machine after a week of tinkering. The problem indeed ended up being in the video card, but it proved to be quite tricky.

I bought a new video card off of ebay. It had the same part number 23030052-212 and looked identical, but the machine would'nt provide any video with the new card installed. After closer examination, I discovered that the original card had a couple modifications. First, a small wire was soldered from the left bottom lead of U24 (S3 Vision 968 Chip) to a spot on the pcb under the Stealth 64 rom. Second, Resister R655 was removed and soldered to the pads to the right of it which was labeled R258 and left empty on the original card. Finally, I noticed a missing surface mount resister R252 along the bottom edge of the card on the original card.

This struck me as odd, as the moved resister had signs of being removed with an iron and flux, but R252 looked like it was ripped right off of the pad. On a hunch - I modified the purchased board to match the original, except I left the R252 component in place. Success! The video worked perfect. It turns out that when the previous owner was reseating the cards, he must have missed the PCI slot and the resister busted off when rubbing against the side of the bus.

He did mention that the problem started after reseating cards, but I figured maybe ESD took out a component.

Now onto the sound issues. I removed the amplfier board from behind the monitor and unsoldered the 13 legged heatsinked part and both electrolitic caps. I ordered the components from Digikey.com for about 10 bucks. The 13 legged part ended up being called a 40watt x 2 channel car stereo amplifier chip. After replacing the three parts, the sound works great and is nice and clear. I beleive the amp chip was the real source of the problem, but the caps are cheap and easy enough to swap out. If your machine has muffled or garbled sound - I recommend replacing the amp chip. Also buy some thermal grease to put between the chip and the heat sink. There was a very small dab from the factory, but it was dried up.

So now my Odyssey works 100% and I've learned a lot about it in the process. I love Phantom Belle Bonus Playoff! Luck Draw is also most excellent!

The only small problem I've noticed, is that the monitor has a little shake right to left once in awhile. Probably a monitor board of flyback that needs some tweaking. For now though, I'm going to enjoy it and worry about fixing that next week.

-Tim

[robertwinter]

Glad to hear you got everything fixed. Thanks for documenting the necessary mods.

On the video board mod, did you need to move R50 to R49 on the back of the board? Odyssey boards have R49 in place and standard boards have R50 in place.
_________________
Robert
http://www.robertwinter.com/slot/odyssey

[Jawbreaker]

I didn't notice that one. I gave the board a quick look on both sides and everything else looked to be the same. I'll pull the new card out later and check. If indeed they are diferent, the Odyssey must not mind.

-Tim