Sega CD 2 Issues

[Dr. Killjoy]

I did some searching on the forums here and couldn't find anything about this posted already, so I'll ask now.

I'm currently working on repairing a Sega CD model 2. I've already replaced the 2.5A fuse on the underside of the mobo and the ribbon that connects the mobo to the CD laser unit (because it was partially corroded). Doing these things allowed the system to boot to the Sega CD loading screen, where it is constantly checking for a disc (and saying that the door needs to be closed).

Long story short, I need to figure out what the door switch in the back connects. I know one side is ground, and that checks out ok. I've been trying to trace out the other side to see where it goes, but I get stuck when the trace appears to stop under the big heatsink on top. I have overridden the switch with a wire permanently soldered between the two switch contact points (since I assumed that the switch itself was bad, what with the corrosion and all).

Any help would be appreciated. Thanks.

[dragonhead]

hit it.

also, the switch may be shorted for lid open, not shorted for lid close.
ill take a look at mine and give you the verdict.

[Dr. Killjoy]

Well, I metered it before taking the switch out, and it made continuity when the switch was pressed. So technically, the switch was probably good; but I didn't want to take any chances.

[Dr. Killjoy]

Just thought I'd post an update. I have the door switch problem taken care of; I followed the guide here for the JVC X'Eye. Now there's a new problem.

I've tested and confirmed that the laser unit is dead, or getting there. The Sega CD is constantly searching for a disc, with the laser bobbing up and down and shining the red light. There is no movement from either motor (the one that controls the spindle or the one that moves the laser along its rail). I've tried adjusting some of the pots, and that produced some results (ie. the spindle and gears twitching). But nothing beyond that.

I managed to find some "model numbers" on the lower board of the laser unit:

EMW10389-003
ENN-395A
NTP-N870A-T

Does anyone have a replacement they'd be willing to give/sell me or know where I can get one?

[wallydawg]

just do the pot tweak. There was a thread at Digital Press about companies that make replacement lasers (trying to find it now) but IIRC it would cost double what a new sega cd would go for.

[dragonhead]

just dig around ebay for another sega cd. not really worth fixing at that point. all mine was dead with was a fuse blow.

[Dr. Killjoy]

Yea, you're probably right. It's just a shame to have made it so far, only to realize that it was over my head from the very beginning. Oh well. I'll keep my eye out for another one, whether it be from ebay, a pawn shop, a garage sale, etc.

[snume]

That high priced laser was for a SCD Model 1 Optima 5s

The SCD model 2 usually uses an Optimna 6s which can be had for around $20

Checkl out this link http://www.electronix.com/catalog/advan ... rds=optima

You will want to take the board out and, if necessary, disassemble the cd unit to get at the laser pickup. Though you may just need to take it out and turn it over with good lighting, but I'm pretty sure there should be Optima somewhere on the pickup.

I ordered 2 from them just a few months ago. This same pickup is also in the X'Eye and some round button Saturns.