TurboGrafx CD suddenly went dead

[Orion Pimpdaddy]

I've had my Turbo CD in my gaming setup for quite a while. I've played it off and on with no problem over the course of two years. I have never moved it from its spot on the shelf. I haven't even unplugged the thing.

The other day I went to play a game: put a disc in, put the CD card in, turned it on, hit RUN, but there's nothing but silence. No spinning, no noise, no vibration. I also noticed the player said "PC" in the tiny light up display (see picture). I'm not sure if it usually says that or not, but I'll point it out anyway.

I have learned about an issue regarding a cheap plastic gear that gives way, but I opened the unit up, and the plastic gear looks good as new. While I was inside, I didn't see anything obvious that would cause it to malfunction.

Anyone have any clue as to why this thing would suddenly croak? Is there a fuse somewhere? By the way, my circuit board knowledge is average. I've soldered new caps into other consoles before, but not much else.

I have the original American Turbografx System, with the CD add-on attached.


6307

[FABombjoy]

My guess is that the laser is stuck. To verify if this is problem, just take the CD out and see if the laser is all the way in towards the hub or of it's somewhere else. The first thing the CD drive attempts to do is reposition the laser and read the innermost tracks, and it will trip a switch in the process that will being the startup sequence.

Depending on where the laser was at the last time you powered it off, it might be stuck towards the end of the disc. They seem to tend towards getting hung up there with age and the design of the ribbon cable only tends to exacerbate the problem (it actually pushes the laser towards the edge of the disc). The only surefire way I've found to cure this is to strip them down, clean, and relube them.

Sometimes you can nudge it along and get it to move again but I would minimize doing this as it will wear out the worm gear follower. If you try this and it works, you should always force a CD reset once you're done using it, so that the laser is back in the inner position. If you're daring, I put together a guide on how to clean & relube the gears (http://console5.com/wiki/Turbo_Grafx_CD_Gear_Cleaning).

"PC" is normal, it just means the CD drive is in PC mode.

[Tokimemofan]

The gear may look good, but it is not. As they age they swell slightly which is what causes the jamming, eventually one of the cogs will shear off or the gear will crack. At the moment there is no permanent fix that doesn't require major modifications to the unit. I managed to repair the problem by removing the gear by drilling the center of the gear and after cutting off the cogs on the top of the gear molding replacement cogs, but that is a week long process. You may consider sending your gear to someone who has a 3d scanner and printer.

[Orion Pimpdaddy]

My guess is that the laser is stuck. To verify if this is problem, just take the CD out and see if the laser is all the way in towards the hub or of it's somewhere else. The first thing the CD drive attempts to do is reposition the laser and read the innermost tracks, and it will trip a switch in the process that will being the startup sequence.

Depending on where the laser was at the last time you powered it off, it might be stuck towards the end of the disc. They seem to tend towards getting hung up there with age and the design of the ribbon cable only tends to exacerbate the problem (it actually pushes the laser towards the edge of the disc). The only surefire way I've found to cure this is to strip them down, clean, and relube them.

Sometimes you can nudge it along and get it to move again but I would minimize doing this as it will wear out the worm gear follower. If you try this and it works, you should always force a CD reset once you're done using it, so that the laser is back in the inner position. If you're daring, I put together a guide on how to clean & relube the gears (http://console5.com/wiki/Turbo_Grafx_CD_Gear_Cleaning).

"PC" is normal, it just means the CD drive is in PC mode.

Okay, I just checked and the laser is at the halfway point. Should my first step be to go inside and clean and lube like in the instructions you linked to? I kind've don't want to do that yet. My fear is that I'll make a mistake and break something.

Also, what exactly is a "CD reset"?

[Tokimemofan]

My fear is that I'll make a mistake and break something.

I'm quite competent at this type of thing and I still broke it. This is easily the hardest system to repair and is one of the easiest to break.

[Orion Pimpdaddy]

I'm quite competent at this type of thing and I still broke it. This is easily the hardest system to repair and is one of the easiest to break.

Crap. :puppydogeyes:

[FABombjoy]

Okay, I just checked and the laser is at the halfway point. Should my first step be to go inside and clean and lube like in the instructions you linked to? I kind've don't want to do that yet. My fear is that I'll make a mistake and break something.

Also, what exactly is a "CD reset"?
Like Tokimemofan said, it's not an easy system to work on and the design doesn't lend itself to long-term stability. The super fragile cluster gear doesn't help either. If you aren't confident in your ability to work with really small, fragile, and easy to lose parts, I'd leave it be.

You might be able to help the laser home by opening the lid an inserting something flat & non-conductive to trip the lid switch. Press 'Start' to begin the process, and gently push the laser towards the hub. With any luck it will start moving again and you'll be off. Once it starts moving that's usually good enough to work for a single session.

"Reset" might not be the best word, but if you can get the laser to the inside before you shut it down, it will be less likely to freeze up like this the next time you use it. When you're done playing, turn the whole thing off & back on, then press start. As soon as the CD spins up, power it back off.

Part of my testing procedure when I refurb one of these is to put in an 80-minute CD and send the laser to the outside. I let it sit for a few days and test it again. It's a long and kind of painful process :D

[Orion Pimpdaddy]

You might be able to help the laser home by opening the lid an inserting something flat & non-conductive to trip the lid switch. Press 'Start' to begin the process, and gently push the laser towards the hub. With any luck it will start moving again and you'll be off. Once it starts moving that's usually good enough to work for a single session.

I think I'll try that. When I move the laser toward the middle, should I then immediately put a CD in while I have still have it propped open?




When you're done playing, turn the whole thing off & back on, then press start. As soon as the CD spins up, power it back off.


So basically I should turn it off twice when I'm done?

[Orion Pimpdaddy]

Well, I managed to get the laser to the innnermost position, but the thing still won't work. I'll try the lube and cleaning techniques. Part of me things that I'm concentrating on the gears too much. I wonder what other things can go wrong with the unit.

[FABombjoy]

With the lid switch tripped, can you see the lens attempt to focus?

[Orion Pimpdaddy]

With the lid switch tripped, can you see the lens attempt to focus?

No I don't see any movement at all on anything. The exception is the circle that snaps onto the disc, which spins a tiny bit, but I believe it's because I'm rocking the unit a when I'm pushing the two turbografx switches to the ON position.

[FABombjoy]

I think the little spin is a normal thing during power on.

Here is a breakdown of what happens after you hit the Start button:

1: Lid switch is checked - if bad, you'll immediately get a warning to close the lid
2: System checks for closed limit switch signaling that laser is at innermost point
3: If switch is not closed, reset laser to innermost point
4: When switch closes, activate laser and check for CD. Lens will move up and down.
5: If disc is detected, bring disc to speed and read directory

The verbose version of this is detailed here: http://www.repairfaq.org/REPAIR/F_cdfaq5.html#CDFAQ_005

It sounds like you're getting stuck at 3 / 4. You can use most digital cameras to verify if the laser is activating (newer iPhones and DSLRs probably not). If you have laser and no focus, the servo mechanism is shot. If you have neither then the limit switch is probably not being tripped.

Did I mention that these things are a royal PITA to service? :D

[BricatSegaFan]

I think the little spin is a normal thing during power on.

Here is a breakdown of what happens after you hit the Start button to being a cd:

1: Lid switch is checked - if bad, you'll immediately get a warning to close the lid
2: System checks for closed limit switch signaling that laser is at innermost point
3: If switch is not closed, reset laser to innermost point
4: When switch closes, activate laser and check for CD. Lens will move up and down.
5: If disc is detected, bring disc to speed and read directory

The verbose version of this is detailed here: http://www.repairfaq.org/REPAIR/F_cdfaq5.html#CDFAQ_005

It sounds like you're getting stuck at 3 / 4. You can use most digital cameras to verify if the laser is activating (newer iPhones and DSLRs probably not). If you have laser and no focus, the servo mechanism is shot. If you have neither then the limit switch is probably not being tripped.

Did I mention that these things are a royal PITA to service? :D

I've been creeping on this thread just out of curiosity, I can say its very informative. On a unrelated note what the hell is your avatar of FABomb?

[FABombjoy]

I've been creeping on this thread just out of curiosity, I can say its very informative. On a unrelated note what the hell is your avatar of FABomb?
Haha, I have no idea what that tan, handsome fella is holding up to his head but it makes me chuckle every time I see it. Some flobee knockoff I think.

[Orion Pimpdaddy]

We're getting off topic.


http://farm9.staticflickr.com/8333/8149340971_a14169bc47_o.jpg

[Orion Pimpdaddy]

Okay, I did as suggested, but first I have to complain about this thing. Reattaching that big ribbon back is a pain. I firmly hold the ribbon, then clamp down the white thing, but most of the time the ribbon falls back out, or is only halfway in. Then, that stupid ground wire soldered onto the plate, well it snapped off somehow. I'll have to resolder that sometime.

Anyway, I rigged the lid, held the camera, and hit run. I don't see anything happening. So the limit switch isn't being tripped I guess. Maybe if I kicked the thing, it might help.

One thing I worry about, and may have already said, is that maybe there's something wrong that doesn't related to the gear area.

[FABombjoy]

One thing I worry about, and may have already said, is that maybe there's something wrong that doesn't related to the gear area.
At this point it appears as such. Bad limit switch, bad servo controller, or other intermediate electrical defect.

I can't recall if these do it, but sometimes when you have a bad limit switch the motor will keep forcing the laser inwards and you'll hear gears clicking. If the factory lube is really chunky the sled motor might not have enough torque to click the gears like that.

Jaguar CDs are notorious for this as the limit switch wires were soldered by Rhesus monkeys.

[Orion Pimpdaddy]

Okay, I'm going back in to lube and clean. I probably do it without disassembling the gear set to minimize the risk. The thing doesn't look like it has any lubricant on it at all, not even residue.

[Orion Pimpdaddy]

SOLVED!!!\\^_^/

I put some lubricant on the worm gear and the tiny silver rail that the laser moves on. I also took the limit switch off and blew into it. Now, that little L-shaped metal piece under the limit switch that holds the worm gear in, it seemed very tight. Maybe it's supposed to be, be it seems so tight that it restricts the movement of the worm gear. So I bent it back a tiny bit to loosen its hold. Someone will probably say this was a mistake, but I was a little desperate and it seems low risk since I can always "unbend" it back into position. After that, I put the limit switch back on.

At least one of the above things did the trick, because the unit is now working. I did a victory dance to the opening music of Splash Lake! The whole operation wasn't too evasive (I only removed the limit switch). If it had not worked, I was going to go back in and do everything in FABombjoy's Gear Cleaning guidelines, but as for now it's working.

Thanks everyone for your help, especially you, FABombjoy.:hail:

The only thing I'm left wondering is whether I should have lubed some of the other items.

[FABombjoy]

Sweet! Glad you got it up and running.

Only the brass worm gear should be lubricated. I've seen other guides that show applying lube to everything, but you really do not want to do that. Adding lube to the gearset will actually increase the effort required to turn the gears. Plastic gears are considered self lubricating. A tiny bit where that L-piece meets the gear probably wouldn't hurt but the preload against the worm gear is probably more critical, as you've found.

I recently serviced a vintage CD changer for a friend and the last shop that worked on it had lubricated everything in site. I actually had to strip it down and de-lube the machine to get it working smoothly again.

[Tokimemofan]

At this point it appears as such. Bad limit switch, bad servo controller, or other intermediate electrical defect.

I can't recall if these do it, but sometimes when you have a bad limit switch the motor will keep forcing the laser inwards and you'll hear gears clicking. If the factory lube is really chunky the sled motor might not have enough torque to click the gears like that.

Jaguar CDs are notorious for this as the limit switch wires were soldered by Rhesus monkeys.

The middle gear would break first. BTW a bad limit switch can be open circuit or shorted, if shorted it will either cause the laser to think it is always at track 0 causing it fail reading or if there is no sanity checking in the firmware it'll slam the laser into the outer edge, if open it detect track 0 and will slam the laser into the center. This applies to 99+% of optical drives. A tiny minority use a potentiometer to define the inner AND outer limit, though I have only seen that in laserdisc players that have tangential tracking mirrors (<1984 units).