Mega CD II doesn't stop spinning

[beebogates]

Hi all,
I got my hands on a used MegaCD II unit from a junk shop. I got home and plugged it into a megadrive II, made the necessary connections and powered it on.
Immediately, the MegaCD's spindle motor started spinning and accelerating, and it sounded like it was going to break. Seriously, the spindle kept spinning and accelerating into very high speeds.. and rattling the tray. I had to pull the power plug and turn it off.
I tried switching it on again, this time with the tray door open and no CD, and again it went into hyper spin. even when the tray door was open.. and clearly it wasn't reading the CD.
Any idea what could be the cause? I have a multi-meter and fairly good soldering skills if anyone wants to suggest any point to start. Really keen on trying to save this console.
Thanks all,
Ahmed

[DemVil12]

CDRom drive controller?

[beebogates]

Thanks for replying! Where is that controller, and how can I test it?

[scrappysphinx]

Hey guys, i have just purchased a Mega CD 2 with exactly the same problems. I have uploaded a youtube vid here to try and demonstrate whats going on. Any help would be greatly appreciated

Thanks

[beebogates]

Hey, yes that happens to me too.. except that it happens even when the door is open!

[MaxWar]

You could use it to make pottery.

j/k

I never fixed something like that, but I would just go through the circuitry starting from the motor and troubleshoot parts. I think the cd-rom comtroller might be a chip that sends orders to the spindle motor, step motor and laser.
I do not know if the chip would power the motor directly but i do not think so, it probably controls an external switch, which might be stuck and then the motor goes full speed all the time?
Do you see the laser moving too?