i have done the requisite googling of course, but i always get better answers on here!

so it’s a 2008 macbook core 2 duo and the back light has packed up on the screen.
screen still ‘works’, ie can see all the right stuff if a shiine a torch on it.
otherwise everything functioning as it should.

have tried reseting the SMC and those RAM things but no avail.
it dii function momentarily when toggleing brightness buttons but gave that up pretty quickly.

quite happy to replace components if someone could help me feel surer about which one. i don’t thingk it’s the inverter, otherwise screen wouldn’t get anthing at all right?
is back light just intergal to screen unit? that’s one thing it won’t make financial sense to replace i reckon
thanks
jimmer

Not sure about macs but I imagine is the same as pc laptop.. Either the inverter board or the back light has popped.

Back lights are generally a really thin compact fluorescent tube, that sits at the Base of the screen plugged into the inverter.

Both parts are quite cheap so for the sake of messing about it might be an idea to replace both if you’re going to DIY it.

But I’m not familiar with Mac hardware so it would be worth double checking it’s a standard set up (as above) before getting the screwdriver out.

Good advice.

Check iFixit for the takeapart instructions [get the correct model].

EDIT – speaking of screwdrivers – also check you have the correct ones, Apple uses a lot of weird screws!

thanks yous.
yep, been on ifixit and got all the right tools, tiny drivers, spodgers etc.

i don’t think it can be backlight since screen lights up perfectly normally momentarily eg when pulgged to external monitor and had lid closed, then open it again.
also, i’ve a feeling i read somewhere earlier that back light is not replacemable by itself. ie is part of expensive screen assembly.
will research further.

if it’s inverter would i even get anything on the screen?

Yes, the inverter powers the HV fluorescent tube, nothing to do with the image/LCD.

From here I’m just guessing, but yeah the tube may flicker when first powered then drop out… Think of a striplight that needs a new starter/bulb (same tech I think).

so you mean it could be the inverter gfs?
yes it did occur to me as i wrote that, that maybe the backlight could flicker on and the go ou tif it’s goosed, liek you say with a strip light.

and have now discovered that backlight is repaceable by itself. saw a vid of a guy who’d found an identical one from a dell and bunged it in. however i don’t fancy that job. just too delicate.

best bet is to try an inverter then i guess since they are only about 15 quid. a screen looks like around 50, which is still not too bad, and a backlight bulb/tube is only from U.S. that i can find on ebay, and needs delicate soldering. not my strong point

I think it’s likely.

Maybe you can test where the problem lies with a multimeter?

i probably could but have never really figured that out. i guess test output from inverter? but it’s huge voltage from what i understand?
just test it on as high a voltage setting as poss in 2 pins, just like a wall socket?

i’ve jsut ordered an inverter off ebay for 15 euros so will give that a try first.

be good to work out multimeter testing tho, as have another pc laptop with no screen sitting doing nothing…

I think you need to Google the pinout of the inverter board and its expected output voltages and try to test them outputs relative to ground.

It would be good to know the voltage, yes, but likely with a decent meter that going over the voltage range on the 750V (or similar Max V) setting will just cause an OV (over voltage) sign on the screen and do no damage.

It may be over volts… but that just means its working 😉

Suggestion – while high voltage low current supplies are usually relatively harmless*, if in doubt keep your left hand in your pocket, so if you get a shock its not going across your heart.

*for a given value of harmless which may be >0 if you have a pacemaker

: )

i don’t have a very good multi-meter, tho i do have a better quality voltage/continuity tester that would handle it i guess.

anyways, i’ll try the new inverter first i reckon.

while we’re at it tho, does all this imply that for the other laptop i have, with a completely dead screen, that it won’t be the inverter that’s the cause?
and therefore what? graphics card, or video card or whatever?
i tried a replacement screen in this one to no avail, so sent it back.
i did drop it on the floor, which caused the failure i reckon, tho a few days after

Might be worth replacing both if possible as dismantling and reassembling laptops is no fun! It’ll save messing with a multi meter and dismantling it twice. Unless you can test it before putting it back together and leave it disassembled while you get the other part.

thanks mattyfez. what are you reffering to there? the mac or the other one i mentioned after?

I had this issue (white macbook, Core2duo) and replaced the inverter board, but it didn’t fix it- I should have waited for the inverter cable to arrive, and done them both at the same time- mine has the same symptoms as yours, and I now suspect that it’s the cable since the backlight occasionally comes on for a while at startup.

It’s a fairly time consuming and finicky job to do though, thus I’d suggest doing the job in one hit. I’m still summoning up the motivation…

thanks vinny.
good to know!
i’m not convinced it’s either, and suspect more likely to be the actual CCFL lamp.
just my hunch since i reckon cable would produce more intermittent on/off behaviour, eg screen properly on at some angles and off at other – not the case with mine.

didn’t find it that much of a hassle to rip apart. time consuming but straight forward enough. but aye, i’ll maybe get the cable too and do them both together.

Uh huh, could be the cable, or a dry joint or…well lots of things. Hence the suggestion to test the inverter.

Eliminating possibilities is the way to go.

Good Luck