Joust player sprites leaving trails.

BrokenTrace

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Turned on the arcade tonight for our friends visiting from across the pond and Joust decides to act up (amongst others).

The initial tests indicate go and are ok when I cycle through them too. The screen is fine when it first comes up and starts, then the players birds leave trails behind them as they fly around. The buzzards are missing a few pixels in the sprites too, though they don't seem to leave much of a trail like the players 1 and 2 do.

I turned it off and on again after 20 min. and it seemed to play fine for about a minute then the trails started again.

Another thing I just remembered is that it didn't boot right up, the batteries don't save the settings all the time, and it stayed in the "reset bookkeeping totals" screen for about 5 - 10 minutes before the kids told me there was a problem. And it has a newer switching power supply installed, about a year old.

Anybody else have this happen to them or heard/seen this problem before? I attached a few screen pics of what's going on.

Thanks,
Brian
 

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I would think that's a RAM issue. but knowing these, it's probably something more complicated, like CPU logic. that's where they tell you to get your logic probe out and such..

haven't done it to my Defender yet, but I encourage you get one of those lithium battery upgrades for your board.

I still got a lot of work to do on my Defender yet before I attempt that. :/

anyway, I would check the RAM chips on the main board, make sure they're all seated in all the way. you could additionally run the game for awhile and feel on the chips to see if any of them get real hot.

if no dice, then I'm sure YellowDog or someone will know what to try next. good luck.
 
anyway, I would check the RAM chips on the main board, make sure they're all seated in all the way. you could additionally run the game for awhile and feel on the chips to see if any of them get real hot.


4116 Run really hot all the time. But hey, feel the chips and see if any are cold. If so you probably have a bad ram. Like mentioned above, check all three voltages going to the rams.
 
imo pull and clean all the chip legs (both game and ram chips), as well as reseat all the connectors (main and ribbon). be careful with the chips tho as those old eproms have some very fragile legs. while your checking out the connectors look for any burn marks on the main connectors (non ribbon cables), if you find any i highly advise replacing that connector as well as the complete header.


checking the voltages as stated above is a good idea as well.


Edit: also use care when pulling the ribbon cables!!! don't pull the cable at all make sure you firmly grab the plastic connector housing (also 1 side is soldered on so that side obviously won't be able to be pulled :D )
 
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Thanks for all the advice.

I turned it on and it played fine for a few screens then reset and got even worse than before. Some serious trails. The buzzards don't leave trails now nor the eggs and when the buzzards and eggs go through an existing trail, they erase the trail from the screen. I attached a few pics of it now.

Also, I checked the ram and felt nothing overly hot. I did see that one of the ribbon connectors from the rom board to the main pcb had no top cover where the ribbon connects to the connector. I attached a pic of that too. It will definitely need to be re-crimped. Never done it before, should be fun....not!

Going to try swapping the rom board and it's ribbon connector with my spare working one first to see if there's any difference, and if there is, then try to re-crimp. I'll report back with the results.
 

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4116 Run really hot all the time. But hey, feel the chips and see if any are cold. If so you probably have a bad ram. Like mentioned above, check all three voltages going to the rams.

Yeah, I neglected that they run hot lol. Isnt that the reason the 4164s are better cause they dont use all 3 voltages?

Id like to replace the ram on my Defender.. as previously mentioned though, I have work to do yet.
 
Yeah, I neglected that they run hot lol. Isnt that the reason the 4164s are better cause they dont use all 3 voltages?

Id like to replace the ram on my Defender.. as previously mentioned though, I have work to do yet.


Correct, 4164 only use 5v and run cool to the touch. You can fry an egg on a 4116.
Im going to guess that is not a ram problem...judging by the pics. I would start by checking all the voltages.
 
Did i miss the part where you checked the +5

The voltages were:

+5.06 coming out of the power supply

+5.03 into the rom board

and +4.86 into the main board

Figured it was the ribbon connector and didn't have the problem with the other board I swapped in. Been on for a few hours now and no problems so far.

And when I tweaked the original ribbon a little, it seemed to fix it and was able to play a few games. Then I tweaked it again, just to see what I'd get and it started trailin' and reseting again. Going to pick up a new ribbon connector and hopefully that will correct the problem.
 
You can try recrimping the ribbon cable. The easist way is to carefully squeeze it in a vise (use a piece of soft wood (pine) behind the ROM card so you don't mess up the pins if you crimp that end).

Most people just grab the ribbon and pull to get the connectors apart. If you can look along the ribbon cable and see the copper IDC pins, it needs recrimping.

ken
 
You can try recrimping the ribbon cable. The easist way is to carefully squeeze it in a vise (use a piece of soft wood (pine) behind the ROM card so you don't mess up the pins if you crimp that end).

Most people just grab the ribbon and pull to get the connectors apart. If you can look along the ribbon cable and see the copper IDC pins, it needs recrimping.

ken

Yeah, you can see the copper pins. Won't be too hard to pull apart. I think that's the problem.

And the back cover for the pins is missing. I have nothing to re-crimp unless I crimp the pins down, and that doesn't seem like a good idea.

Trying to find a new connector. Anyone know where I can find a matching one online? At Fry's maybe?


I have it on good authority that it's a bad SC1 chip.

Is there a way to test the chip? I can pull it too and try it in the working board to see if I get the same problem. The games been running fine for around 4 hours now with the other board in it.
 

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Is there a way to test the chip? I can pull it too and try it in the working board to see if I get the same problem. The games been running fine for around 4 hours now with the other board in it.

Yeah, if you have another board, you can swap the chip between them and see if you get the symptom follows the chip. If it does then you know the chip is bad. If not, then you have a different problem.
 
You can try recrimping the ribbon cable. The easist way is to carefully squeeze it in a vise (use a piece of soft wood (pine) behind the ROM card so you don't mess up the pins if you crimp that end).

Most people just grab the ribbon and pull to get the connectors apart. If you can look along the ribbon cable and see the copper IDC pins, it needs recrimping.

ken

Updating this thread, finally got a chance to work on Joust. Found the back part to the ribbon connection in one of my parts drawers the other day, I re-crimped, and it's been good for a couple of days now. So it looks like that was the issue.

I'd like to add for anybody looking this up that when I played with the ribbon connector while it was having problems, I actually got it to stop doing the trailing thing but then it would constantly reboot when I first turned it on. It would boot, cycle through a few times and then reboot, doing this over and over again for around 5 minutes or so. Then it would finally stop and play ok after it warmed up a bit.

So the funky ribbon connection from the ROM board caused the sprites to leaves trails across the screen and then caused it to continually reset. Re-crimping the ribbon connection resolved the problem.
 
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