I would like to reuse the DVD playing device (ref. TS-P632) from my old SAMSUNG SH893 DVD player (which was still working) and control it with a Raspberry PI. I was delighted to find the service manual for this model on ElektroTanya, and it shows that this DVD playing device has an ATAPI interface (cf. left part of the schematics here attached). It does not look like standard IDE DVD player for PC I am more familiar with, in that it has no MOLEX & IDE connectors. I have no issue with the power source part since i feed the device with its original power source. However on the data part, it has a ZIF 40-pins connectors.
I purchased a IDE to USB convertor  which I plugged to a simple 40-pin ZIF to IDE adaptor  (same as in the picture of the URL, except that I soldered a IDE female connector on the dedicated space).
I tested the convertor separately with a more standard PC IDE DVD player and it works fine. I also did continuity testing on the ZIF-IDE adaptor and it is fine as well.
However, powering on this first setup DVD player => ZIF flat cable => ZIF/IDE adaptor => IDE/USB convertor => Raspberry PI does not work (device is not recognized by the Raspberry Pi, and the LED noted "IDE/BUSY" of the convertor keeps being constantly lighten up, when it is actually supposed to slightly blink in order to indicate BUSYness).
Originally the DVD player is connected with the flat cable to a ZIF connector on the Main PCB, near which are the 7 resistors indicated in the attached schematics (noted DR50 to DR56). I therefore used jumper cables between IDE female connector of the ZIF/IDE adaptor and the male IDE connector of the IDE/USB convertor so as to have 7 pins (#1, 27, 29, 39, 34 and 21, 31) going through a breadboard where i added the resistors as per the schematics and connected them back to the male IDE connector. One end of the first 5 resistors is connected to a 3,3V source (provided by a GPIO of the RPi set on "high") whereas one end of the 2 other resistors are connected to Ground (pin #40 which thus also go though the breadboard).
However with this second setup the device is not recognized either. The LED "IDE/BUSY" does not light up at all this time.
Would you have any suggestion for me?