I just completed a shop job on my Corvette. I was having a problem before the shop job where the red car wouldn't go all the way to the top of the racetrack or if it did it wouldn't reset to the bottom. During the shop job I replaced both internal racetrack boards with the re-designed units from Great Lakes Modular. I also converted the board connectors from IDC connectors to Molex connectors. It passes the track test mode every time and the cars cycle to the top of the track and back down when I boot the game up.

I was playing it last night. Sometimes during a racetrack mode the cars will only go about 1/3 of the way up the track and then it will end the racetrack mode. Does anyone have any ideas on why this is happening? I was beginning to think possibly a bug in the software? My game is running LX-2 software.

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I don't think it's a mechanical issue. It operates smoothly and passes the test mode everytime. I had it apart to put the new boards in it when I shopped the game out and everything looked good. I think I'm going to look for cold solder joints on the under PF racetrack board next.

Tonight I re-flowed all of the connector pins. I put the board back in and started experimenting with the glass off.

What I noticed tonight is that sometimes if you don't hit any playfield switches while in a racetrack mode the cars will only go about 1/3 of the way and end the mode, but if you hit switches it will advance the blue car and both will race to the top. Can anyone tell me if you don't hit any switches in a racetrack mode should the game end the mode before the red car (opponent) gets to the top? I would think you should be able keep trying to catch the red car (opponent's) until it reaches the top and that would end the mode. I guess what I am trying to get at is: should the racetrack mode only end once the red car reaches the top or is it correct if no switches are hit and it ends the mode before either car reaches the top?

I played a few games last night. Everything seemed good with my racetrack at first, but on my last game I started a mode and it ended the mode within about 3 seconds. I don't think the cars even moved, but not for sure on that.

Can anyone tell me what to look at it? This is driving me crazy because the game looks awesome and everything else works great. Could it have anything to do with software or dipswitch settings?

Any help or suggestions is much appreciated.

I also thought one of the cars had to make it to the top to declare a winner, but my racetrack hasn't worked right since I got the game so I wasn't for sure.

I replaced both opto boards with new units from Great Lakes Modular. The opto gap is really narrow on those optos and I doubt something is tripping them, but I guess it's possible. It does declare someone won the race, usually the computer wins, but last night it said I won after about 3 seconds in the mode.

No, I have not tried a factory reset, but that seems like a good idea and I will try that next, thanks!

I've never done this before, but I will mess around with it tonight.

Do you know what I should be looking for?

More bad news. I just went to do the race track test and noticed that neither the ZR1 moved or race track at startup. I tried to run both of their tests in test mode and both failed. I did a factory reset and they still didn't move. I checked all the fuses on the boards in the backbox they tested ok. I looked for an under PF fuse, but couldn't locate one.

Any ideas? I'm at a loss

All 4 coils are there. I did a continuity test on them from the backside of the board and they all had continuity, don't know if that tells us anything or not.

it was closed

Ok, will do this also.

Thanks for all of your advice and help so far

I replaced both boards with the Great Lakes Modular set so I hope that's not the problem, but I will check the opto readings in test mode once I get the track to work again.

Yeah I'm going to check them, but up until last night the cars at least moved, but wouldn't end the modes correctly.

Yeah they both seem to be problematic, especially the racetrack.

Ok, just done looking at a few things, here's what I came up with
a.) fuse 115 and 116 were pulled off the board and both tested fine
b.) TP 1, 2, and 3 all tested normal
c.) TP 7 shows 20v written on the board, I got .5v
d) the top led, D19, on the CPU board isn't lit (it's a Rottendog board if that makes any difference)
e.) ZR1 motor control board in backbox led doesn't light up
f) I noticed a led between c5and c11 on the power driver board that is not lit up, I'm not sure it's supposed to or not, there is no labeling by it.

I just talked to a good friend of mine who know's these games pretty well and he gave me feedback on what I found last night

c.) this is for the flashers and the coin door must be closed to properly check this voltage. I'm not sure if I had the coin door closed or not, I will double check this
d.)this led should turn off about 1 second and stay off. I didn't look to see if it came on at bootup
f.) this is probably a high/low voltage led that might flicker sometimes, but for the most part stays unlit

So seems like I might not have a power driver board problem. I am still curious as to why the led on the ZR1 motor board in the backbox isn't lit.

After a lot of diagnosing/part replacement it turns out the coin door interlock switch went bad and was cutting the power even with the door closed.

Last night we "jumped" the coin door interlock switch and the ZR1 and racetrack started to work again. Same problems with the racetrack though where it would end the mode before the cars reached the top. My friend happened to notice the cars' progress on the dmd doesn't match the cars' progress on the track- see video. The red car is only partially up the racetrack, but on the dmd it shows it reaching the top which ends the mode. This problem isn't limited to just the red car, sometimes the blue car will do it.

I went into test mode and advanced the cars manually, occasionally it would do like in game play where one car would go to the top on the dmd, but not on the racetrack and end the mode, but it does this A LOT more in game play than in test mode.

Anyone have any ideas on what I can look at? As I mentioned the racetrack boards have been replaced with new units from Great Lakes Modular

Video: https://drive.google.com/open?id=0B8LKsouTS1igdllQNm9kTjcwWFE

I just replaced the IDC connector that is on the racetrack board mounted under the PF with a molex connector with trifurcon connectors, no change, cars still go to the top of the track on the dmd and end the race.

So to me it seems like the cpu is seeing a bunch of opto switch registrations at once and that is why the car position on the screen moves to the top so fast when it messes up. It's like something is freaking out the opto signal to the computer, but I don't know what is causing it.

I was going to take the racetrack apart and inspect it, but I don't think the problems in there. All that it is as far as this is concerned is those two boards that are new, two connectors, which I converted to molex and the wiring, which if I remember right is a shrink tube type housing.

Anyone know what could cause the cpu to see a bunch of phantom opto registrations?

I was re-reading the posts in this thread and forgot about this. I looked at the manual, the motor control board and the opto boards in the racetrack both use J116-3 on the power driver board for ground so maybe it could be causing the problem as Cadillac mentioned? I did run a continuity test on the inductors and they all showed continuity, but not sure if that is conclusive or not on considering them good. If I were to replace the conductors does anyone know where I can get them from?

Monday Morning tech help needed bump.

I kind of doubt it has anything to do with the optos. It did this same thing with the original boards and now doing it with the replacement boards. Putting in test mode and manually doing it might show something, but I don't think I can manually turn the wheels since they are inside the racetrack. I guess I can push the cars, but not sure if that would damage anything. I'm thinking it wouldn't because it would just make the string slip over their cogs, but not sure.

My friend and I replaced the caps and inductors on the racetrack motor board yesterday, unfortunately my problem still exists We are considering replacing the LM339 quad chip on the racetrack motor board next. Does anyone know if this chip is anyway tied to the switch matrix or anything else that we might be able to look at?

I think I'm going to do as Kawydud said and bypass the motor board and move the cars manually. I will take the track apart and disconnect the cables that drive the cars, put it in test mode, manually move the cars and see if I get any phantom opto registrations.

Interesting development. I unplugged only the 2 motor connectors off of the motor board and turned the game on. I went into a race mode and to my surprise the car "postions" on the dmd moved, I thought they would stay still since the cars weren't physically moving. Everytime I hit a target it would show the blue car advancing like it should. I did this about 6 or 7 times, the display never showed a car prematurely winning a race like it did before. I plugged the motor connectors back in, turned the game on and on the first race it did just like it had done before showing one car going on the display going straight to the top and ending the race early.

Does that clue anyone into what could be happening?

I wasted about 2 hours on Corvette last night. I took the track off the game and took it apart. Everything looked good. I removed the cables that drive the cars so I could manually advance the cars to see if I got the phantom opto hits. The more I thought about it the more I realized it wasn't going to work because without the cables nothing would turn the opto wheels so I put it all back together; it's a real PITA to re-install the cables and get everything right and it not fly apart in your hands, which it did to me quite a few times.

I re-installed the track, and put it in test mode. I manually pushed the cars up the track and no phantom hits of any source. I noticed every time the opto count hits 670 it ends the mode no matter the position of the car. So it seems to me that in game mode the computer somehow thinks it's seeing the 670 opto count and ending the mode. I wonder if the ROM code might have a bug in it causing this?

I was looking at Corvette some more last night. I ran the racetrack test mode, it passed as always, but I noticed when the cars returned to the start position the zero opto count box wasn't checked- see pic. I manually moved the car about 1/4 inch and it highlighted the box then. I then ran the test a few more times. Sometimes all the boxes would be highlighted and then other times the right car zero position wouldn't be highlighted, then the left wouldn't be, etc.

As you tell I'm having inconsistent results and think this might lead to the problem I've been having. Does anyone have any insight as to what is going on and why I'm not getting all boxes checked every time.

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