video - Back light not workng, replaced laptop LCD, next step?
2014-07
Jack
My daughters laptop LCD went dark a while back, in a dark room you can see that the screen wants to work but will not. I am familiar with laptop repair, have replaced MANY screens. It seems I have been lucky to have the same fix work each time.
I did my usual routine for diagnosis by plugging in an exterior monitor, which worked. So, bad LCD, I figured. Ordered a new LCD, got it, installed it and no video, or should I say the same issue with the original screen. So I ordered an inverter for the laptop, exact type, tried it, no good, same issue. I returned the LCD screen for an exchange, got another one, tried that, still the same issue. I know about the connector issues, and I have been now even more watchful how they go, since I did a second teardown and reconnect on one, a Toshiba, I worked on a few months ago, just to find out it worked after reassembly.
So, bottom line question is, since the only obvious thing left to change is the video cable for this Toshiba laptop, could there be anything else that would cause the same symptom I describe? What throws me on this is the screen works, just not backlit. So if the cable is bad, then just that wire that the inverter is on must be damaged.... just guessing.
Secondly, how likely it is that video cables are at fault? Seriously, I must have changed at least a dozen or two dozen LCD screens over the years, (its a hobby for me) so for me it does not seem very probable at all. I have seen in this site that there have been others with the same problem, bad cable, but there is not way to tell based on that. The most reliable way to know would be of somebody else's experiences, since this is my first go at it.
Mike
I have a laptop where the screen sometimes works and sometimes doesn't. One of the hinges is broken, putting stress on the LCD cable. I have taken it apart now to replace the hinge.
While it is apart do you think that the LCD cable is bad or maybe just loose from the broken hinge? I guess the bottom line is: should I replace the cable while I have it apart or just make sure the connections are secure when I put it back together? Could the inverter also have anything to do with this?
Joshua Nurczyk
I am guessing this is probably a ribbon cable? If not please put more detail in.
The cable(s) would likely be stressed by the bad hinge, but that doesn't mean the LCD itself is not bad. If you can try and spot-check to see if certain positions work better than others (if you're brave enough to turn it on with the case open like that) that could tell you if the cable is bad. I would likely just try and reseat the cable or cables and put it back together, hoping for the best.
Also, of course the inverter could be a problem as well. Just as in a desktop, a problem could be the power supply, motherboard, sound card, memory, graphics card, etc. Everything and anything would likely need to be checked. Unfortunately, without another of the exact same model of laptop its hard to troubleshoot.