T21 screen issue--opinions needed!

[p1763]

hi,

yesterday, while i was using my trusty t21, i began to experience some pretty bad screen flickering. after a couple minutes, my screen went black. now, when i reboot, my screen is nearly black, but upon close inspection, i can see my log in screen, but it is very dark and hard to make out.

do i need to replace my inverter, some cable, both, or something else?

thanks in advance for all opinions...

p1763

[rkawakami]

I'd say that there's normally six things that can kill just the backlight in your display (in my order of decreasing probability):

- burned out backlight; aka, CCFL (especially probable if your display has been showing a pink/red tint at power up)
- bad inverter
- stuck lid switch (if your system has been set to "do nothing" when the lid is closed; otherwise lowest probability)
- loose connection; backlight-to-inverter, inverter-to-ribbon cable, ribbon cable-to-motherboard
- broken LCD ribbon cable (almost zero probability if there's been no physical strain placed on the system recently)
- blown fuse on the motherboard (almost zero probability if you say it was flickering before going totally out)

As the LCD panel is the hardest and most expensive thing to swap out, it's usually suggested that you first replace the inverter with a known working unit. They are cheap (< $10 on eBay) and fairly easy to change out (remove the LCD bezel and it's right there at the bottom). If the system does the same thing, then most likely you are looking at a burned out backlight. However, I'd still run through the remaining items in the list above, re-seating all of the connectors and inspecting the LCD ribbon cable, before considering the expense of installing another display. Of course if you already have a spare T2x lid assembly, then give it a try.

[Unknown_K]

Sometimes you can see one end on the CCFL is black (I checked a 13" screen on a T2x that had backlight issues and that is what I found). On units as old as the T21 it is probably not much cheaper to buy a new bulb compared to a used screen assembly, but you don't know how long the bulb in that screen will last. Replacing the blulb itself requires some work and soldering.