Marble Madness trackball sensitivity/speed

chubsta

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I have just taken delivery of a Marble Madness and am having a slight issue - there are the 'jumps' on the first level where you can gain extra seconds, but try as hard as i can i cant get the ball rolling fast enough to make the jump, even if i use both trackballs at once. I didnt have any issues back in the 80s doing this so i guess it could be an issue with the trackball not translating its movement fast enough - anyone got any suggestions? There is a tiny bit of movement in the ball so could it be bearings etc?
 
I'm almost positive that there are no sensitivity settings to adjust for the trackballs. On mine, I can make the jumps you are referring to.

Either you are having issues with your trackballs or with the circuitry that interprets them.
 
Thanks for the reply.

I have examined the trackballs and there is minimum wear so not really sure how to proceed with it but the marbles definitely don't move as fast as they should given the speed the trackball is moving...

May have to do more research I think...
 
could it be bearings etc?


I would say 90% yes.. replace the "bearings" and "rollers"... very easy to do. Make sure you order for a 3'' Trackball. It's 20.00 from arcadeshop.com and will be the best 20 bucks you ever spent... I bought a set for my centipede MAJOR difference. (again mines a 2 1/4"...make sure you get the 3" set)

3inkit.jpg


Item "3" Atari Trackball Kit (6 Bearings and 3 Rollers) " - $20.00... http://www.arcadeshop.com/parts.htm
 
Hi,
I have sent a message to them about ordering a couple of the kits, hopefully it will make a difference as i cant see me getting anywhere in the game at my current speed!

Let me know if you get a response, cos I sure as hell can't, sent them two emails which have been ignored for shipping price for 2 items.
 
Bob Roberts has all the trackball roller kits as well and he usually replies to your email order within the hour or so.
 
Bob Roberts has all the trackball roller kits as well and he usually replies to your email order within the hour or so.

Bob Roberts has some good stuff but I'm in the UK so it's really difficult to pay for orders from him. I have ordered the parts from arcadeshop (very good service so far BTW) so hopefully it will fix the issue. If not then I guess the next step would be to replace to optical boards...
 
OK, I am happy that it is not the bearings etc, so that is one possible thing solved! I have been researching more and from what i can gather the 'Leta' chip is responsible for interpreting the trackball movements, can't locate it on the board though. One thing that i heard could be an issue was the +5 coming from the ARIII - i have checked this and it was a little low so have adjusted it to a rock-solid +5 and that hasn't fixed the problem...

So, next step was to give the optical sensors on the trackballs a really good clean - they were a little grubby but not too bad, unfortunately that has not solved the problem...

So, to recap, i have marbles that move and accelerate but do not move fast enough.

I have cleaned the trackballs and optical sensors, replaced the rollers and bearings
I have adjusted the +5V on the ARIII

Nothing has fixed it so far...

Any help and advice would be gratefully received as i really want to play this machine!

Cheers,
Karl
 
Bumping for a little advice as it is killing me! I have removed and reseated the LETA chip with no improvement. I guess there is no way of telling if it is faulty without some hi-tech equipment?

Also, there is an LED just above the LETA chip - should this be lit?

If i were to be able to source a replacement LETA chip, is there anything else i can do before fitting it apart from checking that the +5V to the main board is ok? Obviously if the origional chip has failed it has failed for a reason and i would hate to do that to a new one...
 
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Bumping for a little advice as it is killing me! I have removed and reseated the LETA chip with no improvement. I guess there is no way of telling if it is faulty without some hi-tech equipment?

Also, there is an LED just above the LETA chip - should this be lit?

If i were to be able to source a replacement LETA chip, is there anything else i can do before fitting it apart from checking that the +5V to the main board is ok? Obviously if the origional chip has failed it has failed for a reason and i would hate to do that to a new one...

I'm pretty sure the LETA chip isn't socketed.
 
Bumping for a little advice as it is killing me! I have removed and reseated the LETA chip with no improvement. I guess there is no way of telling if it is faulty without some hi-tech equipment?

Also, there is an LED just above the LETA chip - should this be lit?

If i were to be able to source a replacement LETA chip, is there anything else i can do before fitting it apart from checking that the +5V to the main board is ok? Obviously if the origional chip has failed it has failed for a reason and i would hate to do that to a new one...

Now... I've never had to replace a LETA yet but apparently they do die. Not sure where on the pcb it is but I am sure you can download the schematics somewhere to check. Are replacements available for this? If not you are down to looking for another Atari game with the chip in and buying it just for that. If you fancy making your own google 'jrok leta' and start having a read....
 
Fortunately the LETA is socketed, i have tried reseating it with no luck. May well have found a new one so will have to see if it works out and fixes the problem. If not then im kind of stuck as to what the issue could be...
 
Bumping again in case anyone has any advice - i played a few games in mame today and by adjusting the sensitivity of the analogue controls i was able to play the game as i remember it, making jumps and stuff. However, when i play my cabinet its still the same old slow plod around for the first 2 levels and then i run out of time on the third...

Any help or advice greatly appreciated..
 
Well, today i received a new LETA chip, which unfortunately doesnt seem to have solved the problem! I am almost totally at a loss now as to what is causing this issue - the trackballs are fine and running ultra-smoothly, the leta chip must be working unless i got another one with exactly the same fault which is unlikely, there are no errors on the tests etc.

So, all i am left with now is the game roms themselves, could it be possible that the roms i have do not allow for movement above a certain speed, any advice again would be very much appreciated befor i give up and try to sell it....
 
bumping an old thread here but I believe I am having the same issue. anybody have any new ideas now 10 years later?
 
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