Neo Geo CD Frontloader Repair Help Please

Rasubosu

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Hello everyone, longtime lurker turned member here requesting help from anyone who might know what's going on with my frontloader. I tried posting this much earlier today but something happened and my post disappeared (think I got timed out) so I'm attempting to post this again.

Edit: I know someone else posted about their frontloader today too, if we're having the same problem I apologize for the redundancy!

I've owned a toploader that's had no issues and I just got this frontloader not long ago so I want to get it fixed. It's something I've wanted for a while and the serial number is in the 600s so I'm guessing it might be pretty early production out of the 25,000 or so that were made.

Here's what's going on:

>system turns on fine, boots to main CD screen
>disc tray ejects on command
>insert disc, nothing happens
>disc tray ejects by itself

I popped the top off and noticed that when you insert a disc the drive doesn't lift to engage the magnetic top. I pushed the tray up manually to engage and the disc doesn't turn, keeps stuttering and everytime it stutters it goes back to the NEOGEO CD opening and keeps doing that.

>turn system off and back on
>disc starts turning
>main CD screen says press start to begin
>game loading screen appears
>once load meter gets to 100% the screen goes blank
>returns to NEOGEO CD opening and goes back to the CD menu

I tried removed the disc and tried again only to hear a grinding noise and the disc started stuttering again causing the system to keep turning on and off going back to the NEOGEO CD opening.

I did find a few bits of plastic inside that I have no idea what they were originally attached to, one almost looks like a clip to me.

Anyone know what might be wrong? I can post pics of the bits if need be. Thanks for your help!
 

Rasubosu

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Update:

So I dissected the frontloader best I could and further inspection into the machine showed that the random rattling and plastic bits are mostly from this.

neogeo2.JPG

One of the plastic parts holding the disc drive down broke at some point but the integrity of the other three are strong and keep the drive from moving anyways. There are still a couple of really small plastic pieces that I can't figure out where they came from.

I was able to figure out where the disc drive is failing but short of taking the tray apart (can't seem to figure out how) I won't be able to get into where I need to go to figure out what's wrong. There's a little gear wheel that turns as the tray ejects and closes. The gear wheel is supposed to turn enough to cause the gear or piece that manages the lens tray? (not sure what to call it, sorry) to come up and engage with the magnet at the top of the drive. Something is preventing this from happening for some reason.

I pushed the lens tray up manually to engage and the disc started spinning like normal with some minor stuttering. Doing this I was able to get an audio CD to play perfectly without any issues. I did the same thing with a game and had mixed results.

The first time I tried this when I first made this post I wasn't able to get past the 100% at the load meter. This time it went to the title screen and allowed me to select a game mode.

neogeo5.JPG

Within the first few seconds of the first game mode it reset. The CD drive then made a grinding noise as it tried to play again. Turned the system on and off and got it working again. This time I selected a different game mode and played into level 2 with no issues then it reset. Third time tried a different game mode and it reset quicker than the second game mode. Tried the second game mode again and it reset quicker. I tried the various modes and the reset points seem to be at random. The disc is near mint and the lens seems to be clean enough to allow me to play through at least several minutes of the game.

I'm wondering if the plastic pieces that I can't identify came from the disc tray and are what allowed it to lift and engage the magnetic piece at the top. They don't seem like it but what I'll probably end up doing is figuring out how to take the tray apart and check in the spots that I can't get to. Any and all advice is welcome.

Here are some photos of the tray with the problem area highlighted masterfully in MS Paint. The yellow circle kind of shows the gear wheel that is supposed to turn in a certain way to activate the bottom lens tray circled in red. The red arrows are what that little part needs to do but isn't doing.

neogeo4point2.jpg

Here are some other photos of the insides and a photo without the MS Paint doodles.

neogeo.JPG
neogeo4.JPG
neogeo3.JPG


I'm going to keep at it and see if I can figure it out but hopefully someone can steer me in the right direction because I have no idea what I'm doing lol. I've worked on a lot of consoles but this is the first Neo Geo anything I've opened up.
 
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CHAOS 0187

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Feb 28, 2016
Posts
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Update:

So I dissected the frontloader best I could and further inspection into the machine showed that the random rattling and plastic bits are mostly from this.

View attachment 46501

One of the plastic parts holding the disc drive down broke at some point but the integrity of the other three are strong and keep the drive from moving anyways. There are still a couple of really small plastic pieces that I can't figure out where they came from.

I was able to figure out where the disc drive is failing but short of taking the tray apart (can't seem to figure out how) I won't be able to get into where I need to go to figure out what's wrong. There's a little gear wheel that turns as the tray ejects and closes. The gear wheel is supposed to turn enough to cause the gear or piece that manages the lens tray? (not sure what to call it, sorry) to come up and engage with the magnet at the top of the drive. Something is preventing this from happening for some reason.

I pushed the lens tray up manually to engage and the disc started spinning like normal with some minor stuttering. Doing this I was able to get an audio CD to play perfectly without any issues. I did the same thing with a game and had mixed results.

The first time I tried this when I first made this post I wasn't able to get past the 100% at the load meter. This time it went to the title screen and allowed me to select a game mode.

View attachment 46505

Within the first few seconds of the first game mode it reset. The CD drive then made a grinding noise as it tried to play again. Turned the system on and off and got it working again. This time I selected a different game mode and played into level 2 with no issues then it reset. Third time tried a different game mode and it reset quicker than the second game mode. Tried the second game mode again and it reset quicker. I tried the various modes and the reset points seem to be at random. The disc is near mint and the lens seems to be clean enough to allow me to play through at least several minutes of the game.

I'm wondering if the plastic pieces that I can't identify came from the disc tray and are what allowed it to lift and engage the magnetic piece at the top. They don't seem like it but what I'll probably end up doing is figuring out how to take the tray apart and check in the spots that I can't get to. Any and all advice is welcome.

Here are some photos of the tray with the problem area highlighted masterfully in MS Paint. The yellow circle kind of shows the gear wheel that is supposed to turn in a certain way to activate the bottom lens tray circled in red. The red arrows are what that little part needs to do but isn't doing.

View attachment 46502

Here are some other photos of the insides and a photo without the MS Paint doodles.

View attachment 46504
View attachment 46506
View attachment 46503


I'm going to keep at it and see if I can figure it out but hopefully someone can steer me in the right direction because I have no idea what I'm doing lol. I've worked on a lot of consoles but this is the first Neo Geo anything I've opened up.

If the tray is opening and closing with the no problem, the I think the mechanism highlighted in yellow is intact. Try taking apart the kit that holds the lens. It is held down by 4 screws with springs. There maybe some pieces of plastic there keeping it from going up and down. Hope this helps some what and good luck!
 

HeavyMachineGoob

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Apr 3, 2011
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5,815
I remember opening the NGCD Front Loader I used to have and thinking to myself, "The CD drive looks exactly like the one in a Sega CD Front Loader".
 

GadgetUK

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Posts
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Looking at the photo with the gear there - looks like a missing tooth to me! If you cannot find a replacement gear, don't give up - consider manufacturing a tooth for it (eg. a tiny piece of epoxy to fill the gap between the teeth, then some very fine work with files once it hardens to build a tooth back up - but success is not guaranteed and patience is the key.

neogeo4point2.jpg
 
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Rasubosu

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Posts
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Looking at the photo with the gear there - looks like a missing tooth to me! If you cannot find a replacement gear, don't give up - consider manufacturing a tooth for it (eg. a tiny piece of epoxy to fill the gap between the teeth, then some very fine work with files once it hardens to build a tooth back up - but success is not guaranteed and patience is the key.

View attachment 46564

Oh wow, do you think that might be the issue? I'll take a closer look at it once I get home. As far as I know that gear only moves the lens back and forth but that might explain why it stops working mid game. Thanks for pointing that out!

I'll also try your suggestion Chaos 0187. Still need to figure out why the tray isn't activating.

I went out of town for a few days so I haven't had much time to tinker with this. Might work some more on it tonight. Thanks for your suggestions everyone!
 

GadgetUK

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Oh wow, do you think that might be the issue? I'll take a closer look at it once I get home. As far as I know that gear only moves the lens back and forth but that might explain why it stops working mid game. Thanks for pointing that out!

I'll also try your suggestion Chaos 0187. Still need to figure out why the tray isn't activating.

I went out of town for a few days so I haven't had much time to tinker with this. Might work some more on it tonight. Thanks for your suggestions everyone!

I've never seen the drive of that particular model, but in some front loaders what happens is the main carriage gears (for moving the OPU) are used to drive the loading mechanism too - ie. it moves the head all the way to the stop position, then something dissengages and the motor keeps going and is able to drive another gear which then lowers or raises the carriage and ejects / pull in the tray. Basically I would inspect how the tray is driven - is there a belt or gear, where does it connect? Does it have a seperate motor for it, or is it linked to that head gear system? It might be that they are totally seperate faults. It might also be a case that the gear that drives the tray is missing a tooth also...
 

Rasubosu

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I've never seen the drive of that particular model, but in some front loaders what happens is the main carriage gears (for moving the OPU) are used to drive the loading mechanism too - ie. it moves the head all the way to the stop position, then something dissengages and the motor keeps going and is able to drive another gear which then lowers or raises the carriage and ejects / pull in the tray. Basically I would inspect how the tray is driven - is there a belt or gear, where does it connect? Does it have a seperate motor for it, or is it linked to that head gear system? It might be that they are totally seperate faults. It might also be a case that the gear that drives the tray is missing a tooth also...


Interesting. Thanks a lot! I didn't have a chance to take a look last night but I don't have anything planned tonight so it'll be tinker time.
 

Rasubosu

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Edit: I added some descriptions to the photos

Ok so I completely disassembled the tray to see what makes it tick and I learned more about how it works. Only the white gear is missing a tooth but I found the replacement for it. I guess it's a common part made by Sony that has a high failure rate in a variety of systems. I'll be ordering this to replace it, I'm almost positive that's why the disc keeps resetting after a while.

Now the main question is why the tray isn't lifting to engage the magnet. Nothing looked broken when I took the tray apart so nothing is getting stuck or causing any problems there. The little belt thing seems to be in great shape. However, I noticed that the full range in motion for the gear isn't being utilized for one reason or another and that could cause the tray from lifting. I'm guessing it can be one of two things. The gear with the broken tooth may have something to do with how the other mechanisms work by not being able to work fully on its own. The other thing could be that motor thing in the photo below that controls the disc belt is going bad and isn't working 100%, restricting the full moevement of the gear. Not too sure about any of those.

My only step at this point is to see if the games run perfectly fine with the new gear installed. If they do then the motor controlling the belt could be suspect since nothing else seemed odd. Still not sure where some of these plastic bits came from though.

View attachment 46599

This is the view inside, the area with the white lubrication is the thing that is supposed to lift the tray, that is controlled by the same gear that brings the tray in and out and that in turn is controlled by a belt and a motor
IMG_2968.JPG

These are the random broken pieces I found inside. Not sure where they came from
IMG_2972.JPG

Maybe this is going bad??
IMG_2971.JPG
 

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Rasubosu

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GadgetUK

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It's very unlikely to be the motor. I would suspect those broken bits of plastic tbh, or a slipping belt (or combination of the two).
 

Rasubosu

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It's very unlikely to be the motor. I would suspect those broken bits of plastic tbh, or a slipping belt (or combination of the two).

That's what I can't figure out. I looked over everything and can't find where those bits came from. I'll post more once I get the new gear installed, hoping that does it.

I did purchase a working frontloader CIB recently that should be slowly making its way over from Japan that I can reference eventually if I don't get this fixed before then! Pretty stoked on that :D
 

Rasubosu

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Ok, so over the weekend I installed the new gear for the laser and it didn't fix the issue of the tray not lifting. Didn't really have time to really get in depth with anything else so I'll be taking a closer look either tonight or tomorrow. If it fixed the resetting during gameplay then that'll be one less thing to worry about!
 
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