Chosen Solution
A few months ago I bought a second hand C50-A-157 on Windows 7 which worked until recently. Last week, I switched it on and the screen appeared to be blank however; if I shine a torch on it, I can see the desktop very faintly. When I removed the screen bezel, there was the screen, camera and assorted wires but no inverter. Thus, using the part numbers off the original, I ordered a replacement screen panel (NT156WHM-N50) and a video cable (1422-01EH000) and fitted them, but to no avail. I’m back at square one. Any suggestions please?
ron.atkinson you have a problem with the backlight circuit on your motherboard. There is no inverter and the backlight is driven from the motherboard not the replacement screen. toshiba is a paranoid company that does not condone having their service manuals show up enywhere. So if anything you can try by giving us any information that is printed on the mother board. Look for makers/model numbers etc. Let us know what you find. Without a schematic it will be very difficult to determine where the fault is. Of course you do want to consider posting some good images of your motherboard with your question. Use this guide Adding images to an existing question for that. It will allow us to see what you see.
If the Toshiba has a external output like most laptops, check to make sure indeed the video adapter is functional by connecting it to an external monitor. If that checks out, then the symptom seems to point to loss of backlighting. Your model is an LED backlit monitor so the circuit on the LCD would be handling that functionality. Either you got a DOA replacement panel and/or cable or worse, the driving circuit. I would try both cables. Otherwise the problem would seem to be the laptop motherboard panel driving circuit.
