Sega CD model 2 grinding noise

I have a Sega CD that makes this loud grinding/buzzing sound for 2 seconds when it first turns on but it never happens again. I've tried everything to make it stop from inspecting every tooth on the gears, disassembling the CD drive, trying to adjust that safety mechanism that stops the laser from going off the track which was supposed to fix the issue but it's still not working. There's nothing wrongwith booting discs or anything besides this annoying ER-ER-ER-ER sound at startup.

This is a 60 second recording of around 20 reset cycles. Sometimes it doesn't even happen and sometimes it drags on forever.


http://www.datafilehost.com/d/f76354ff

 

I have exactly the same with one of my SegaCD's. I am almost sure, that this sound is coming between motor which moves laser head and gear. You need to turn it on and see what is happening during that sound.

 

It's when the laser hits the start of the track. On YouTube there's a video of s guy who fixes his model 1 by bending the safety mechanism which is a piece of plastic the laser hits at the start of the track to tell the drive it's reached the beginning and not to go further but it didn't fix mine.