Sega CD 2 (Samsung assembly) issues

[fahlim003]

Since Sega-16 as been useless, I figured to try here.

I have a Samsung lens assembly fitted Sega CD 2 recently and learned it did not power on. I replaced the fuse and while there is life now there is still an issue. The lens assembly moves the opposite end of the rail (furthest away from the spindle motor) and continues pushing the assembly thereby grinding or kicking back. When a disc is inserted it will check it a little then proceed to push the assembly to back endlessly. I'm not sure what the issue is so any help is appreciated.

[FABombjoy]

It does so regardless of lid being closed / disc present?

[fahlim003]

It does so regardless of lid being closed / disc present?

Sorry for the long delay, but yes it does so regardless.

[FABombjoy]

Is there any possibility that the lens motor may have been wired or plugged in backwards?

Does manually tripping the inner-track limit switch stop it at all?

[APE992]

Is there any possibility that the lens motor may have been wired or plugged in backwards?

Does manually tripping the inner-track limit switch stop it at all?

I'll bet the switch is either broken or being ignored.

[FABombjoy]

That's what I'm thinking too, it's just odd that the laser is running to the outside instead of the inside. But if the motor was reversed...

Shorted BTL driver is another thought.

[fahlim003]

When the cover is opened and closed, the "access" light pulses and with a disc inside it seems to try and read it but no avail - the lens is pushed to the far end of the assembly and pushed continually. If it's the door sensor/switch, I've read these can't be repaired, correct?

[FABombjoy]

We are talking about the inner limit switch, which tells the CD controller that the laser is all the way towards the CD hub. The fact that yours runs in the opposite direct and clicks is what is strange. It sounds like your lid switch is probably fine.

In mechanisms where the inner track switch fails, the laser goes towards the hub and clicks because the controller never gets the signal to stop the laser motor. So if yours is going in the opposite direction, that's why I'm wondering if there is any chance that a motor was replaced incorrectly.

Looking at pics online of the Samsung assembly, it appears that there are several connecting plugs. Is it possible one could be reversed, or that one was de-pinned and reversed? I don't have a Samsung Sega CD or I'd test it myself.

[fahlim003]

There are 3 connecting plugs. On the mainboard they all have different sized jacks (9, 8, and 6 pins) however the 9 & 8 pins both connect to 8 pin connectors on the rear of the lens board (as the 9 pin jack only has 8 wires to begin). I tried swapping the two 8 pins and the result was the same. Here are close photos of the assembly.

http://imgur.com/a/MkeJM