Problem with backlight for display NEC NL6448BC33 – 59

[antani]

Hi,

any time ago the backlight of the display panel NEC NL6448BC33 – 59 stopped to function so i ordered it on Ama and replace it.

After 5 minutes stopped to again so i think could be the inverter

i tried to supply voltage to this unit (+12Vdc) to try again the backlight but no response...(maybe died backlight after replacement)

It's impossible to find the same inverter because manufactured from the house of the equipment where display panel is placed (Simrad)...

It's not possible to send in repation or find another same unit (Simrad CX 44 for boat radar) because is obsolete and out of production since few years.

This is a big problem because if no repair solution the owner of the boat have to change all equipment installed on the boat because there's no compatibility with a new unit (instead of Simrad CX44 out of production)

Any ideas to solve? (please don't say to change boat! )

Thanks

 

[Nigel Goodwin]

It would be fairly unusual if you could just stick power on the inverter, and it works - there are five wires connecting to it - one is probably enable, one would be brightness, and the last probably a feedback error signal to allow the processor to shut everything down in case of a tube fault.

There seems little on the inverter board?, is there a chip on the other side? - if so, google it's number and try and find a datasheet.

 

[antani]

It would be fairly unusual if you could just stick power on the inverter, and it works - there are five wires connecting to it - one is probably enable, one would be brightness, and the last probably a feedback error signal to allow the processor to shut everything down in case of a tube fault.

There seems little on the inverter board?, is there a chip on the other side? - if so, google it's number and try and find a datasheet.

In the other side there aren't components (only extend ground metal surface).
Unfurtunally this inverter is produced and remanufacturing from Simrad and not in commerce so i find only other data sheet type but with more wire (8)

 

[antani]

It would be fairly unusual if you could just stick power on the inverter, and it works - there are five wires connecting to it - one is probably enable, one would be brightness, and the last probably a feedback error signal to allow the processor to shut everything down in case of a tube fault.

There seems little on the inverter board?, is there a chip on the other side? - if so, google it's number and try and find a datasheet.

At example this inverter for the same display has more wire and components:

https://store.lcdparts.net/104PW161_p_4260.html

so is not possible to connect on my mother board (5 wire connector)

 

[antani]

at this link there is a video where on the display is connected a different type of inverter with less wire by a adapting cable with only the signal base (the original inverter has many wire, maybe ten...and the replace inverter has only six but used only four)

https://store.lcdparts.net/UB54220LED5620X1MS610UBMS534EXT-for-104-LCD-screen_p_5995.html

i don't know how to find the other signal on my inverter...i found only the power supply...

 

[antani]

i would try to make an external pilotage circuit with new inverter....but i don't know where to start!

 

[antani]

isolved with stripe of led and external power supply 12 Vdc