Sega CD woes (Model 1 &2) Need help or advice

[sparf]

Hello everybody!

So, I just moved into a house with a spare bedroom that has been turned into office and retro-game space. So I naturally wanted to haul out the SegaCD/Genesis/32X combo to its place of honor. I've been storing my consoles with the system units together in a dry, climate controlled environment. My preferred unit, just because it's so gorgeous, is my Sega Genesis/SegaCD Model 1 combo. The bonus is that my genesis has a modded region switch in the back for imports. Anyway, I hooked up the system and, voila, it would not accept the tray being closed. So I have pulled the system apart and tried, completely unsuccessfully, to figure out how to re-align that big black gear so that everything lines up properly. I have found all sorts of posts and videos and none of them show me exactly what I need to know in order to be able to align it properly.

So, I said screw it and went to Amazon and found someone selling a model 1 which didn't power up. I figure it's the fuse issue, but what I wanted was the drive assembly so I could swap it out if it was working and use my much more well-maintained unit. Unfortunately for me, the new drive behaves in the same way! I haven't tried to fix the gear on it because I have proven inept at fixing the other one and would like to not repeat history. But is it likely that two drives would do the same thing in a system, or is there something else that could be wrong at the system board level?

Does anybody have photos of exactly how to align that gear? Maybe a step by step guide to the complete repair with photos that I haven't located?


GENESIS 2 Problem: The drive unit refuses to function. It grinds the gears because the laser somehow isn't tripping the laser armature sensor switch in order to tell it it's reached the end of its track. Despite the slightest touch of a cotton swab or my finger shutting off the motor when the circuit board alone is hooked to the ribbon cable, when reassembled the unit still grinds and won't function.
******EDIT:Attached are photos of the switch in question. I have scoured electronics sites but I don't know what this thing is actually called on the Model 2. Anybody out there who could help with that I would love you forever. I have tested just the circuit board attached to the system and when I barely touch the switch, it shuts off the laser motor. But the minute I attach gears and laser back to it, it doesn't stop the motor any more.

Please, help.

[sparf]

Okay, so I am still having no love from the Sega CD Model 2. That switch is something that nobody I know who knows electronics has ever encountered, so I don't know if I could re-solder it if I needed to. But the thing is, I get continuity through the switch when it is touched by the laser assembly. I don't know if it's pushing enough to make the contact more than intermittently. If I could think of some way to extend the plastic housing even a couple of millimeters would probably be enough to make certain the switch trips.


HOWEVER, I have news on the Sega CD Model 1 front. Thanks to Oldskool's post in another thread that I found in a search just today, I opted to look into the drive belt rather than the timing gear for my model 1.Oldskool posted this:

I always recommend a new belt too. It can cause all sorts of odd things to happen, the most common one is that it will eject the cd as soon as you put it in. Just because the belt looks ok doesn't mean that it is. They get stretched and have a difficult time raising up the laser assembly. Although, technically if you manually set the disc/laser assembly into the proper position you are basically doing the work of the belt. So for testing purposes it's not needed much.

Another thing - people worry too much about the aligning of the gears. They are engineered so that if they are out of place they somehow always end up back in the same position. I noticed this after trying to adjust gears for hours and hours, they always seemed to reset back to a default position. I think this is an engineered fail safe so that if the gear ever slips the console can set their positions. It achieves this when the laser assembly has been fully raised the gear will keep turning until it hits the stop on it. Of course if you have a worn belt it will not raise the laser assembly all the way up which will make you think it's the gears. Rather than wasting time with the gears (that are rarely ever actually broken) focus on the belt, the laser assembly hinges and the limit switches.

in This Thread I have no replacement belts, so I looked up this video on Youtube: http://www.youtube.com/watch?v=xJJyELdj6t4, which showed me how to fully access the belt.



Even more importantly, the poster of the video made note that you can test to see if the belt is the issue by soaking the old belt in hot water for a few minutes and then replacing it. If the unit functions more readily, then that is likely the problem with the old constant door-opening problem.

He linked to this site: http://www.studiosoundelectronics.com/belts.htm#SBM with a recommendation for using part number SBM 3.0 (which as of the time of this posting costs $2.00 per belt)

I also took a look at the replacement unit that I bought (which did not power up) to gut for its drive assembly and found a scorched power board much like the one in this thread:Sega CD Model 1 Burnout. So I'm going to try to emulate what I see there with some solder and some replacement parts and see if I can't get the second unit up and running too.



I'd really still appreciate any help or thoughts on the Model 2 though, if anybody out there has any. At this point I've had the drive assembly completely apart as I mentioned before. And for some reason when I plug in just the logic board and trip the switch by hand, it will shut off the laser motor but when I reassemble it, even though the switch shows on my multimeter as tripped (I disconnect the power while holding the laser armature in place to check), it's not shutting off. It's odd.