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Question

Titanium Powerbook G4 Intermittent Dark Screen

Oct 6, 2012 7:00AM PDT

Sometimes this machine works perfectly. More & more frequently the screen starts to shimmer, then goes dark. It's not off, because I can see a faint image of the screen, but it's very faint & dark. Sometimes by closing & re-opening screen it will come back to life. Sometimes increasing the brightness with the brightness key will cause the dark condition to occur. I'm very capable of repairing what needs to be done if I only knew what to do. TD

Discussion is locked

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Answer
Sounds like a failing backlight,
Oct 6, 2012 8:59AM PDT

usual fix for this is a replacement of the LCD screen.

It has to be the one that is exactly the same as the existing one for it to work.

You "may" be able to replace the backlight itself but that is doubtful.

Look on ebay for replacement LCD's for your machine

P

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Answer
I agree.
Oct 6, 2012 10:32AM PDT

While it's usually the backlight or one of the cable+components the intermittent open and close should be a clue to the person you take this for repair. No offense but it appears you are not the repair person so be sure whoever does this knows the symptom.
Bob

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Replaced Display
Oct 6, 2012 10:54AM PDT

I actually did replace the display myself last year and everything worked perfectly for at least 6 months. I'm just hoping for something a little simpler as a fix. Am I dreaming? TD

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That re-inforces that
Oct 6, 2012 12:29PM PDT

It could be a connection problem. Keep in mind the connections are 5 year designs. It's a dirty secret in the industry.

Did you go back in to unplug and plug it all back in?

A tech calls that "scrubbing the contacts." I call them "good techs."
Bob

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Scrubbing The Contacts
Oct 6, 2012 3:23PM PDT

This sounds like a good starting point.I assume you mean the internal contacts for the LCD cable or LCD inverter board? Is there some some sort of non-residue cleaner that one should use? By "5 year designs" you mean they will fail around that time or just need scrubbing? TD

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Sorry
Oct 7, 2012 2:47AM PDT

But a failure is a failure is a failure. It does not mean it's OK if we go inside to unplug and plug to scrub the contact and it works again that this is not a failure. So here we are with an industry that is pushed by us to deliver lower and lower priced products and they did what we asked. Most folk don't want to know how we got here.

I'm unsure why it matters but why not go in and do the usual work? Beats the heck out of new boards and displays.

Finally what is this talk of cleaner? Did you spill soda or such on this? Those lifespans are about how much material they put on the contacts. For example you can flash some gold on contacts for longer life but then it costs more. Flash twice the coating depth and you end up with much longer lifespans but now we are getting into material studies.
Bob

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No spills ever
Oct 7, 2012 2:56AM PDT

Nothing's ever been spilled on this. So when you say scrubbing contacts you don't mean cleaning, you mean the coating needs to be re-surfaced or built up? I'm always the guy to keep old stuff working so I'm open to any ideas. I'm going to open this back up, inspect all cables and contacts and see what happens. TD

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Inspect?
Oct 7, 2012 3:15AM PDT

Sorry but there was this one tech we had that didn't last long. They would not follow the direction to unplug and plug in the connections but would "look" at the connection and if it looked plugged in, would not unplug and plug it back in.

They lasted a few months.
Bob

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If I may jump in here as there seems to be a bit of
Oct 7, 2012 4:36AM PDT

a disconnect with the term "Scrubbing"

The action of unplugging the connector and plugging it back in is called Scrubbing the Contacts.

Also known as Reseating

No physical scrubbing, re-coating or cleaning

P

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I'm into it!
Oct 7, 2012 6:34AM PDT

Thanks for all the advice. I'm into the disassembly and I'll report back. TD

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Scrubbing Done
Oct 10, 2012 11:33AM PDT

Well. I scrubbed all the connections and no change. And then someone made a clever suggestion that I connect an external monitor and if that works then the the inverter is good and the screen itself is defective. If that's good logic, then I do have a bad screen because the external monitor is steady & bright, Yes or no? TD

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Kinda,
Oct 10, 2012 9:53PM PDT

An external connected to your laptop, and working correctly, indicates that the graphics card in the laptop is functioning correctly.

Everything else on the laptop that comes after the graphics card is bypassed in this scenario so this is not a reliable method of checking whether the inverter or backlight is functional.
The inverter on the laptop supplies the power to drive the backlight of the internal monitor and,
assuming that the external monitor is of the LCD type, it will have its own inverter and backlight built in.

P

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Answer
Your tiBook is at least ten years old
Oct 15, 2012 11:40AM PDT

and the ribbon connecting the monitor to the logic board could be brittle, and have a short in it.

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Answer
Another option
Oct 26, 2012 9:52PM PDT

I had this happen to my MacBook. The Mac Store technician said that it would cost more than it was worth to replace the screen. So I purchased an external monitor and got an old keyboard from an old iMac and hooked them up to the laptop. I now use it like a desktop computer.

May be an economical option if you don't want to put too much money in it and don't need to carry it around.

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It is well known and common problem with iBooks G3, G4.
Oct 27, 2012 1:26AM PDT

The graphics chip soldering to the mother board is a bit "cold" - in electronics engineering/industry the joints that fail are called "cold joints". Depends of the chip packaging design they have pins or bubbles under the chip. Specially bubbles are bad news in portable computers where the mother board flexes as the whole computer (note book) flexes and graphics chips getting very hot. With time some of the bubbles or pins become "cold joints". As the different pins/bubbles are used for connection to in build LCD and external monitor the either monitor may stop functioning.
The to fix this problem is re-solder the the offending chip - in case bubbles it is a quite a challenge, one needs special soldering tool, with pins is a bit easier but again one needs a "fancy" soldering iron or special head on the iron to the job.
In Denmark years ago the courts ordered the Apple to repair iBooks free of charge as it is design fault - and it is when you think about it. Specifically titanium iBooks are very flexible. Engineers did not think while designing the note books. It happened to me with 17" iBook and as well 12".
Regards ..... K

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Add to that they removed the Pb.
Oct 27, 2012 6:06AM PDT

Without Pb the solder is now more brittle. Lots of studies and the result is short life spans in many products.

I'm unsure if the removal of Pb actually reduced waste.
Bob

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Lead in Solder
Nov 7, 2012 5:15PM PST

There's nothing you can do about the removal of Lead from the Solder. Industry wide there was an issue with Tin based solder replacing the Lead solder. However, this was an EU ruling that became legislation (ROHS), so without adhering to it, Apple Can't manufacture goods in Ireland for European distribution

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Answer
Re Intermittent Dark Screen
Nov 7, 2012 5:28PM PST

The Dark screen issue is one of three things:

1) The Backlights are failing. Can you vouch for the age of the replacement screen in your TiBook? The titanium Powerbook used Sodium/ Mercury power backlights- just like flourescent tubes although smaller as the backlights.
2) The cables that run through the hinge are failing (rotate the screen around the hinge (partially opening and closing- does it flicker then?).
3) The Inverter board needs replacing (the brightness key issue points to this, but also the backlights. It does not indicate a cable issue). The inverter board is located in the screen assembly directly below the LCD. It literally inverts the supplied power to a voltage sufficient to drive the backlights themselves.

I do not believe that it is solder to the GPU (Graphics chip) as you would have no video at all. I also do not beleive that it is anything to do with the video signal cable (flat ribbon cable) running from motherboard to screen or the display (LCD) itself. This is isolated to the actual backlights and or their power source.