Marantz dv4001 tray open - Marantz DV4001 DVD Player

CD/DVD players use a protocol;
Open tray. Insert disk. Tray switch tells mechacon that the tray is shut. Attempt to focus on disk.
If focus is acheived, then it will spin up and try to read the disk otherwise it will ask for a readable disk.
If the tray keeps opening, I would suspect the tray detect switch is malfunctioning, maybe the drive belt has stretched.

Well if you want to DIY you should open the coves, spay some oil on the mechanics and ensure they are running smoothly, if you spray grease on lens you will damage it, be careful.

https://www.youtube.com/watch?v=RcVn9NUtq0c

https://www.youtube.com/watch?v=tgatBVzXH5M

https://www.sony.com/electronics/support/articles/00025399

YES, UNPLUG, REMOVE SCREWS @ BACK & SIDES, CHANGE FUSE ON POWER BOARD,OR YOU CAN TRY & RELEASE THE TRAY BY WINDING THE COGS BACKWARDS. CHECK YOUR PLUG FUSE FIRST.

You might have to open the player and see why. remember to unplug till you need to see if you can get it to work or not.

In this case, you should use YPbPr (component) type of connection. It will allow you to watch TV in HighDef. without HDCP conflict.

Unplug the AC ..Let it set for a few minutes. PLug it in.
If no display still , it may be the backlight for the display that's quit.

Let me know,

Scott

It sounds like the HDMI port on the back of your Marantz is damaged. if you know for sure that the HDMI port works on another tv still you might just use component connection because the visible difference between component and HDMI is not very recognizable.

Open the case and take it out manually.