help connecting tft screen from dvd player

[Ivan.L]

Hi All

Some days ago my friend gave me parts of a portable dvd player. the parts were:
The main board
The lcd controller board
The inverter

The problem I have with them is that he desoldered all of the wires.




My biggest problem is the inverter. It has 3 wires. Where I should connect them and what voltage?

Thanks in advance!

[mahjongg]

the inverter generates a high voltage for the indecent gas tube for the LCD backlighting, on the input (if there are only three wires) I guess would be one ground wire, (probably originally black) one power wire (probably originally red and for 12V) and one wire for "control" that is either on/off or "brightness", and this is probably a 5V (digital) signal, referenced to the GND wire.

Be careful, an inverter like this makes several hundred volts AC at its output, (at the left hand side) that can be deadly!

I would first identify the GND, probably it is the large track on top.
Then I would examine the "royer oscillator & controller" iC, and would google for it, if you can find its data sheet, it will tell you the VCC voltage it uses, and which pin is connected to it, which you can use to trace back to the power wire.

[Ivan.L]

the inverter generates a high voltage for the indecent gas tube for the LCD backlighting, on the input (if there are only three wires) I guess would be one ground wire, (probably originally black) one power wire (probably originally red and for 12V) and one wire for "control" that is either on/off or "brightness", and this is probably a 5V (digital) signal, referenced to the GND wire.

Be careful, an inverter like this makes several hundred volts AC at its output, that can be deadly!

I would first identify the GND, probably it is the large track on top.

The problem is that I got the inverter without the wires and there is no writing on it. I know where the ground wire is and thats all.

I tried googling for mst710 but I couldn't find any datasheets.

[klricks]

Your only options are to:
Get your friend to show you how the wires were connected.....
-Or-
Look at a similar unit and compare....
-Or-
As mahjongg suggests find data sheets on chip(s) and trace back with an ohm meter....

You did not mention what you want to accomplish with this, but if your intent is to somehow connect this to a RPi to use as a display then I think you will no be able to do that. Most players have video outputs only ...... not inputs (HDMI or composite) which would be required for the RPi (or anything else).

[Ivan.L]

Ok guys.

Yesterday I checked the ic on the display driver. Now I checked the inverter ic and found the datasheet for it.
I found that the two pads on the pcb lead to the ic. One is a power input and the other is chip enable.
The input voltage is from 6V to 17V.
I plan to use it as a screen for th RPI. How many amps my power supply must provide at minimum?

The display driver has 5 pins:DVD/TV,TV/C S_Y,GND and REM.
also the main board has composit input.

[GTR2Fan]

The input voltage is from 6V to 17V.
I plan to use it as a screen for th RPI. How many amps my power supply must provide at minimum?

There's no way of knowing just from the required supply voltage.

[klricks]

Ok guys.

Yesterday I checked the ic on the display driver. Now I checked the inverter ic and found the datasheet for it.
I found that the two pads on the pcb lead to the ic. One is a power input and the other is chip enable.
The input voltage is from 6V to 17V.
I plan to use it as a screen for th RPI. How many amps my power supply must provide at minimum?

The display driver has 5 pins:DVD/TV,TV/C S_Y,GND and REM.
also the main board has composit input.

What is the brand and model of the DVD player?
Google that and see if you can find a user-manual with specifications for the power supply.
If you have never used the RPi on composite then I would suggest that you try it on another working composite display or TV.
IMO composite is not usable for a main display. ...... Poor quality low resolution and jittery hard to read text.... Some do OK with it though.

[Ivan.L]

Just tested the inverter with the screen using my 2.5 amp 12v power supply.
It works
Now time to start with the display adapter.
looks like it even does not need 5v on the chip enable pin to activate it.
All I know is that this dvd player is from sony.

[Ivan.L]

I think that the display driver uses s-video input. The tv/c pin is color and s_y is image. If I connect the two pins to the composite out of the RPI it will work.

[Ivan.L]

Tried feeding video through all pins except the rem pin but it doesn't work. What does the rem pin do?

[basicmark]

Not sure, but are you sure those aren't output pins (i.e. for playing the DVD through a TV rather then the built in display)?

[Ivan.L]

Not sure, but are you sure those aren't output pins (i.e. for playing the DVD through a TV rather then the built in display)?

The pcb connects to the lcd so I'm pretty sure that they are the input pins.
The pcb is the one on the second photo.

[klricks]

FYI
Some players have a switch to change the composite from output to input.
Some must be switched by using the remote or other keys on the console to get into the OSD menus.

[Ivan.L]

Just connected the display driver to the main board. Got the same black screen. What should I do next?