My younger brother has a problem with his Advent K4000 we both don't have a slightest clue how it happened or how to fix it, so many a member on this board might have an idea. Basically the backlight just doesn't turn on at any time (BIOS/OS/etc) the laptop itself is functioning correctly and all, since you can see it very faintly in the screen when you've got sun shining on it for a bit of light or when it's plugged into a Monitor. Maybe it's a connection that's mysteriously come lose? I'm not sure how since it's just sitting on a desk 100% of the time. And tilting it slightly trying to see if the light will turn on at an angle doesn't help either. Anyone got an idea?
Bad connection is possible, but I'd rather expect that either the inverter or CCFL tube is gone. Did you get a red-ish (or maybe even flashing) display before? If so, your CCFL died; otherwise, if the problem just appeared out of nowhere, it is most likely because of a bad inverter. Try to find a service manual for the laptop, it should describe how to replace the inverter. At least for the devices I had to deal with, this is some small PCB than can be exchanged quite easily; i.e., not built onto the mainboard. If it turns out your CCFL is bad, you have a real problem, as these are usually not meant to be replaced. Even if sent in for warranty, the service center will usually replace the whole display unit. It is possible to replace the CCFL yourself, though, but I recommend not to even begin trying unless you have a very steady hand and quite some experience with a soldering iron.
Thanks for the support guys, I'm guessing it's a bad inverter then. I'm not much of a electronics wiz but I'll definable try and find the service manual see if there is any useful information in there.
Having dealt with this before, my first guess would always be the CCFL bulb. They're about 10-15 on eBay and aren't really that hard to replace. You just have to be willing to take the assembly apart. The actual soldering isn't that hard. More properly described it's high in the pain-in-the-ass factor, but low in the actual difficultly factor. -hl718
If you've got an LCD panel floating about, you can test to see if it's the inverter or not. Open the LCD panel and there will be 2 or 4 connectors with 2 wires in them, take the laptop screen apart and find the connector it goes into and swap them around for just one connection and try it.
Also be careful when testing the inverter/ CCFL as they generate high voltages. Probably not enough to kill, but will give you a nasty shock either way.
Would an Anti Static wristband be okay to replace inverters or CCFL's without running the risk of being shocked?
No, they stop static from you blowing parts, on inverter boards you usually (like in PSUs) have high capacity capacitors which store the charge, touch them and you'll feel the zap. Drain the power from them.
It is most likely to be the inverter, but that doesn't rule out the tube (or a simple wire issue). It's better to suspect the inverter first, as it's screwed to the housing, whereas the tube is inside the screen itself. You don't have power on to change an inverter, unless you fancy a 700V jolt. When replacing parts in a laptop, ALWAYS take the battery out first! Oh, and NEVER wear an anti-static strap when dealing with a live circuit!! This is basic electronics - anti-static straps earth you. You won't need a service manual, Advent is a cheap, shitty brand (that's what you get from buying in PC World, though)! Just remove the screws in the bezel, unclip the bezel and unscrew the inverter. Either get the proper replacement, or if you can't find that, a universal inverter.
