iBook Clamshell SE dim screen

[dudejediknight]

Well, it seems my beloved Clamshell has run into a bit of a problem. The screen doesn't want to light up anymore. It still seems to be working, since I can faintly see the desktop and everything. I opened it up enough to see that none of the connectors on the lower half were loose or noticably damaged. I haven't yet opened up the screen end of it, for lack of a take-apart manual for just the display section.

My research seems to indicate that it could either be the backlight bulb or the inverter board. Anybody have suggestions as to how I should proceed? What would be the best way to check which part is causing the problem? The screen itself is still in great shape, so I doubt a full transplant would be worth the trouble at this point. Other than the dim screen (and the previously mentioned dead battery), everything else is running fine.

I do have a Dual USB iBook with the dreaded logic board video problem which could donate parts to the Clamshell, provided they are actually compatible. My Clamshell has been a great machine since I got it (it's lasted way longer than the Dual USB one did), and I'd very much like to get it back up and running as soon as possible.

 

[Patnukem]

I think it may be an inverter issue if its related to the back light or possibly the back light is going out like you said, i did not see that you wrote that before I must be tired! anyway apple suggests this for troubleshooting a dim screen.

1 Adjust screen brightness setting.

2 Verify that backlight cable connection is secure.

3 Check display cable and inverter board connections to the

logic board.

4 Verify that cables are not pinched or severed.

5 Replace inverter board.

6 Replace display.

7 Replace logic board.

 

[tomlee59]

The easiest test is by substitution with a known good backlight. I believe, but am not certain, that the dual USB's backlight is fully compatible with the clamshell's B/L. At minimum, it's electrically compatible, so for a test at least, it will suffice.

That said, in the absence of an electrical test, we can infer some odds: If the B/L was yellowish and dim prior to going out altogether, then the backlight itself is likely the problem. However, if it was bright and white before suddenly going out, then the inverter is probably the problem.

 

[dudejediknight]

if it was bright and white before suddenly going out, then the inverter is probably the problem.

It was perfectly fine one day, and the next, it just didn't. My instincts thought it was the inverter, but until I get a chance to try a replacement, I can't be completely sure. Does the backlight bulb still get power if the inverter is the problem? Is there some way I could check with a voltmeter to make certain before I start ordering parts?

 

[Patnukem]

I think the inverter could be broke if the bulb was dim if it was under powering the bulb due to it failing. but then again it could be the bulb going, I agree with trying a different inverter then a different bulb, the inverter should be a lot easier to get to then the bulb unless you where to get a whole new lcd assembly with everything in it then it would be easy to fix.

 

[Christopher]

I think the inverter could be broke if the bulb was dim if it was under powering the bulb due to it failing. but then again it could be the bulb going, I agree with trying a different inverter then a different bulb, the inverter should be a lot easier to get to then the bulb unless you where to get a whole new lcd assembly with everything in it then it would be easy to fix.

I'm just the man to fulfill that. I have a Blueberry LCD in case and all. just needs a home. And any other Clamshell parts you need, except logic boards.

 

[tomlee59]

if it was bright and white before suddenly going out, then the inverter is probably the problem.

It was perfectly fine one day, and the next, it just didn't. My instincts thought it was the inverter, but until I get a chance to try a replacement, I can't be completely sure. Does the backlight bulb still get power if the inverter is the problem? Is there some way I could check with a voltmeter to make certain before I start ordering parts?

If the inverter is bad, the typical failure mode is no or low voltage applied to the tube. When operational, a backlight gets on the order of 1000V AC from the inverter. A voltmeter is certainly a good way to determine whether the inverter is dead, but note the voltage, and take appropriate precautions. A functioning inverter can bite you very badly! Also note that the voltages may exceed the safe input range of many modern multimeters.

The suddenness with which the failure occurred is consistent with a failed inverter, but additional testing is the only way to be certain.

 

[equill]

... a backlight gets on the order of 1000V AC from the inverter ...

As high as that? Ouch! It warrants pause for thought, then. My only data of that kind come from PB100 series, the blue 160 inverter board (922-0025) and the green 180 board (922-0024) specifically, which are marked on the boards as 350VAC and 400VAC outputs respectively.

However, my scribble-book reminds me that there are more part numbers for other PBs in the 100 series (699-0273 and 922-0375 at least), and I don't doubt that Apple could have used much higher voltages for later PBs.

de

 

[coius]

Let me put in my thoughts:

Usually, Backlights go out slowly. on top of that, they will display a redish hue the same way the other flourescents do like as overhead lights.

Inverters are the ones that work one second, then not the next. As I work on laptops, it's the most common symptom of a failing invertor. Just look for an inverter on eBay. REMEMBER, you MUST get the same one as the one in your current screen. Failing to do that can result in damage to electronics that is attached to the inverter

The inverter is the cheapest part you can get. If it's not the inverter (the inverter is most likely the problem) you will need a new screen. That's more expensive, but you must get the EXACT inverter for it. I found this out the wrong way a long time ago.

Noting that, this exibited the same symptoms as my friend's iBook G4 inverter problem. after getting a new one, it was fixed.

That's my knowledge from working with laptops (which I have done almost 50 this year with this problem)

 

[tomlee59]

... a backlight gets on the order of 1000V AC from the inverter ...

As high as that? Ouch! It warrants pause for thought, then. My only data of that kind come from PB100 series, the blue 160 inverter board (922-0025) and the green 180 board (922-0024) specifically, which are marked on the boards as 350VAC and 400VAC outputs respectively.

However, my scribble-book reminds me that there are more part numbers for other PBs in the 100 series (699-0273 and 922-0375 at least), and I don't doubt that Apple could have used much higher voltages for later PBs.

de

Yes, one can receive quite a painful bite from these inverters. The nominal operating voltage is roughly proportional to tube length, and the striking voltage is often about 50% higher than that. If a tube fails, the inverter periodically retries to start the tube, so the worst shocks paradoxically can occur when the tube is dark.

 

[LCGuy]

Ayup, a few years ago I was working on a PB145B (which I didn't realise I had left ON), when I plugged the backlight back into the inverter board. Result? One stuffed cable, black mark on finger, and one LCGuy thinking, "whoops, I left that ON!"

 

[julieA]

Hi,

I think that my blueberry has run into every problem in the book, and a few that are not in the book....

I used to rush to the tech, and get it fixed, but it got to expensive, so i started using the web, stumbled on this site -

http://www.fixya.com/support/p523135-apple_ibook_blueberry_b4914ll_mac

used it a few times, was never sorry.

I highly recommend it.

Enjoy your Mac!!!

 

[dudejediknight]

I hate to resurrect a past thread, but I finally found the solution to my problem. I would have gotten to it sooner, but one of my drives on my desktop (my startup drive with all my stuff) decided to go wonky. Took a couple days to go through the retrieve & repair operation for that, which just killed my motivation for a while there.

Also, it took me a while to find one at a decent enough price ($30.00 plus shipping is just too darn expensive for me at this stage), but I did finally find a replacement inverter board on eBay. Pulled the machine apart, made the switch... and now it works great again. Now I can get back to that darn battery problem, as well as move on to the other pressing things on my list.

 

[tomlee59]

Glad you finally fixed it. The "it worked one day, then next day not" behavior certainly tended to point to an inverter problem, rather than a CCFL tube problem. Happy to hear that it wasn't something exotic or complex.

 

[adric22]

Hey guys.. I was just googling looking for info on my clamshell and found this thread. Strange to find it on a 68K mac forum. But anyway, I just received a blueberry clamshell that I paid nearly nothing for. It works, but the backlight has a pink color to it for the first several minutes of use. After a while it turns white but if the monitor goes into dim-mode or shuts off due to the screensaver for even a few seconds, it is pink again when it lights up.

I am sure this is the backlight tube as I have seen regular compact fluorescent lights in my house due this. I was thinking of replacing the tube. I found one website showing a decent instructional on doing this. But I was also wondering how feasable it would be to replace the tube with LEDs. I was wondering if anyone has tried or thought of that.

 

[tomlee59]

It's possible, and has been done by lots of folks (google, and you'll see). However, it's not a trivial mod. You can't reuse the CCFL backlight electronics, so you have to figure out a way to obtain the requisite low voltage/high current for the LEDs. Then, you have to devise a way to connect and fit several LEDs in the small space allotted.

My suggestion is simply to buy yourself a replacement CCFL tube and be done with it. It'll last another 10 years, by which time you'll have moved on.

 

[adric22]

My suggestion is simply to buy yourself a replacement CCFL tube and be done with it. It'll last another 10 years, by which time you'll have moved on.

I understand what you are saying. But I've been looking for an excuse to try it for a while. Electrically speaking, there is no problem. I am sure I could find a place to power the LEDs and probably even use a transistor or something from the backlight signal to allow it to turn on and off, possibly even different brightness levels.

The trouble is, I've never looked at the spot where a backlight is supposed to go. I do not know what to expect as far as how much room I'd have to work with and whether or not the light has to be uniform all the way across like a CCFL would be or could there be small spaces in between the LEDs?

 

[coius]

btw, since this was brought up. IIRC, all iBook LCDs had two tubes in it. It was common for the displays to get dim over time. Indicating that one of the tubes failed a while ago (sometimes they just stop working on one of them, and it's dim because only one is left lighting it). So if you have a red hue from it, it's the last bulb going out. The bulb will also go out after a redish hue presents it out as it is unable to sustain the power going through the tube. It could be anthing from a leak in the tube, to the cathode/anode not working right (the most common of them) and eventually, it can't get enough power to keep the bulb lit.

Keep in mind, replacing a bulb in an LCD is not a trivial thing. You must take an awful lot of care in doing so, and make sure that you place the actual LCD part on a soft cloth and move it out of the way. Handle the screen on BOTH sides so it doesn't crack by slightly flexing if you only hold it on one edge.

Replacing tubes is a trial and error, and sometimes it can't be done. No matter how delicately it's done, just sometimes even not being careless can cause issues.

The upside is when replacing them, you do NOT need to worry about polarity. So whichever side you connect the wires to, it will light.

I recently worked on a screen that the guy said was going dim over time, and finally got really dim, and started making a red-hue.

I opened it and found that 3 of the 4 tubes died. The last one was hanging on by a thread. And that one was display red. It was almost unreadable, but I am surprised all the tubes would go over so quick (2 years) and the manufacturer wouldn't warranty it (they stopped the warranty at 90 days. Cheapskates) which I also found out the displays had a ton of issues across the net. It was notoriously known for the Backlight issues.

When picking a bulb, you MUST get the exact Millimeter length tube. Failure to do so, will result in a tube that's long or significantly shorter than the LCD. causing either improper lighting, or not being able to put together. So when you go to order a new tube. Open up the display.

It starts at the part that the glass tubes starts on either side. DO NOT MEASURE THE LEADS!!! This is NOT part of the tube length.

I will look up a great ebay I order my tubes from. Great guy, and very flexible. When I ordered the wrong size tubes, instead of returning them (he says they were too delicate to survive shipping [which I actually believe since they are extremely thin]) he gave me a discount on getting replacement tubes that were the RIGHT size.

I will repost as soon as I find the guy. He has always come through. Quick shipping and a good price for the tube.

 

[coius]

this guy:

laptoplcdparts

I highly recommend him. I get ALL my replacement tubes through him. Not a broken tube in the 30 or so orders I have gotten from him. He sends them in a pvc pipe secure and makes sure the tubes have enough protection.