Please help

I have recently worked on some battery issues and have encountered a fault with DVD stack - constantly flashing ? I have reconnected a few times but no joy, I have taken apart & removed discs, none jammed. I am now stuck any ideas anyone?

I have read this on another site, does anyone agree?
removing the battey with disc inside was a very bad idea
they get confuse when you power for the first time try to open the unit and remove the disc
but when all the lights start flashing it means that there is to much damage inside.

Or does anyone have any suggestions for aftermarket one to fit or best place to pick up one or Single stack type?

Cheers