LCD MONITOR PROBLEM

Hello to all members
I need a help for my lcd screen on my tractor
It has two problems
First of all, it does not power up, the voltage is good(12V) and Can-Bus signal also good
Secondly,the 12V Bulbs for night lighting are Also not working
What do you think?




I would start cleaning the six contacts in the black power connector and its soldered pins underneath; confirm continuity health of the light bulbs and voltage supplied to power pins of the integrated circuits. Their data sheets will tell where are they supposed to get +V.
Probing can take some scraping/piercing of the impermeable coating.

Externet said:

I would start cleaning the six contacts in the black power connector and its soldered pins underneath; confirm continuity health of the light bulbs and voltage supplied to power pins of the integrated circuits. Their data sheets will tell where are they supposed to get +V.
Probing can take some scraping/piercing of the impermeable coating.

Click to expand...

Hello Sir, Thank you for your response, but i don't Have a circuit only for 6 pins
I must track it with multimeter

... read again, slowly...

Externet said:

... read again, slowly...

Click to expand...

Hello Sir, i see what are you said and this time we execute it but the problem has not solved yet,i think is an internal power supply problem but i can not find it
We tested the lamps, are good but no resolution yet
The display has 6 pins
PIN-1 12 Volt Supply
Pin 2: CAN-L Signal
Pin 3:CAN-H Signal
Pin 4 :Not used
Pin 5:Signal it is connected to GND
Pin 6:Lamp Control:Connected common to GND with Signal pin
First of all i want to ask,why lamp pin is connected to signal pin and GND, is lamps powered by transistor?
I forget to mention that LCD has not backlighting
Thank you

With pin 1 feeding +12V and pin 5 to (-)ground, probe with your voltmeter the exposed pins of the components nearby the black connector, that is the black rectangles and the round silver capacitor for +12V presence, come back with results.

Do you mean the display has never had backlight before or only since failed condition ?
The lamps can have +12V taken from the board and by grounding pin 6 can turn on; or reverse, the lamps can have (-)gnd from the board and by feeding +12V to pin 6 can turn on. A transistor on the board could also switch them on. Unclear how it works.