Sega CD Model 1 Tray Issues (Belt Replaced)

[reverb | 0]

Hi everyone,

 

I recently got a Sega CD Model 1 that had some tray issues, and I replaced the belt to not successful change.

The tray tries to return back in when I press start, but it just... doesn't. I linked a video to show exactly what's going on. 

I am potentially thinking it could be the switch I've heard about; however, I am not sure. If anyone has seen something like this before let me know!

 

 

 

[FireHazard51 | 2,043]

I'd say a switch/sensor for sure.  Replacing the belt/band was a good call for how old it is.  I'd also recommend using some lithium grease on the moving parts.  Looking at the video I can see the black belt driver trying to spin.  Though I'm not sure if it's trying to spin in the correct direction.  Maybe the tray is trying to open even further because it doesn't realize it's open all the way (sensor/switch doesn't signal it's all the way open).  I don't have a Sega CD to try but I know on old CD stuff you couldn't half way open and get it to close.  I'd need to fully open before closing.  If it's like the latter then I'd say what ever switch is suppose to be triggered isn't or the contacts are so dirty it's not completing the circuit.  

Why it stutters when it opens.... hard to say.  If everything is greased then a loose connection to the electric motor?  That seems much harder to troubleshoot.  But for why the tray won't close.  I have a good guess on that one and how to trouble shoot it.

1. Find the switch/sensor that the tray hits when is fully open.
2. Make sure the tray is triggering it.  Simple switches will often have a bit of plastic push the switch closed.  If the plastic bit is broken off then that is your problem.
3. Make sure the switch complete the circuit when engaged.  You'll need a multimeter that checks for continuity.  Pretty basic stuff for even cheap meters to do.  If it doesn't complete the circuit then spray some contact cleaner and engage the switch a bunch to help the cleaner do it's job.  Retest for continuity.  Hopefully it works.  If it doesn't you need a new switch which I'm sure is standard part but who knows how to identify that specific standard part.  It's a cheap part that you may find in another cheap electronic device or you could order a random assortment to then find a replacement one that fits with some luck.
4. If the switch is making a closed circuit then I'd say trace the wires and see if there is a bad soldier joint somewhere.  This could be absolute pain if it's not obvious where there is a lose joint.

[reverb | 0]

The switch works fine, and the traces test good too. I would like to note this is the JVC CD assembly, not the more common Sony one. 

I tried taking the tray out to see how it acts while I manually hold it to the "open" position. Only when I press the first reset, then move the switch to the open tray position, the motor/gears stop briefly, then continue trying to eject further (clockwise). No matter what I did, I could not get the motor to go counter clockwise.

 

I just can't figure out why the thing is permanently trying to eject.

[CMR | 520]

It's just a guess, but it may be a bad transistor or logic chip if works by using them like relays to power the motor.