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PowerBook 170 screen & battery

Posted by: martona on 2012-07-14 19:31:16 Hi, First the simple question: I have a PB 170 with an (understandably) dead battery. There are a number of replacement batteries available on Amazon and they're not particularly expensive either; does anyone have experience with these? The abundance of offerings comes with a total lack of feedback on Amazon, so I thought I'd ask here. Second, and this is a bigger deal: the screen looks a bit problematic. After a few minutes of use the corners start to turn black and they remain dark for a while even after the machine is powered off. Photos: Any thoughts on what could be causing this? Something tells me it's not an easy fix... TIA!

Posted by: Byrd on 2012-07-14 19:59:59 The PB1x0 battery is relatively simple and I'm surprised they still sell them, needless to say make sure it has been made recently, not ten years ago. If they offer a warranty, go for it! The display on active matrix 170's is subject to "vignetting" due to the CCFL backlighting wearing out over time. It's not as common in passive matrix displays. Have a search around these forums, some have suggested replacing the capacitors on the inverter board can help (albeit this is not confirmed), and/or replacing the backlighting with an LED strip (again, no-one has done it ... yet). THe PB170 is one of the best 68K laptops made I reckon - they just ooze class with a stylish design, decent performance and (when it works) a great display. Mine did the same vignetting and I ended up finding a junker PB170 which I was able to switch the LCD over to. JB

Posted by: beachycove on 2012-07-14 21:41:29 What? The black creeping tunnel is a known defect in early active-matrix lcds, and is unrelated to the backlight. It does not affect all these screens, but those exhibiting the symptoms are irrepairable. The problem was identified and turned up on forums years and years ago. Passive matrix screens can, however, be repaired as suggested. The only known cure is a replacement screen in your case.

Posted by: martona on 2012-07-15 00:36:34 Thank you guys for the quick responses! Looks like I'm in the market for a donor machine then.

Posted by: nvdeynde on 2012-07-15 12:20:00 You'll need good luck to find a replacement active matrix LCD that doesn't have the problem. It's a very common problem, not only for the Powerbook 170 but also for other models with an early active matrix LCD like the 180, duo 250, 280, 540,... Your best option would be that you actually can test the screen before you buy the laptop. Leave it turned on with a white background for 2 hours to make sure. Some panels show the problem in less than 10 minutes, others only after more than 1.5 hour.

Posted by: martona on 2012-08-06 21:26:40 I guess I got lucky 🙂 I bough a bundle of three PB170s off the 'bay for a few bucks, they were "parts only" for sure as they literally came in several pieces each. Fortunately there wasn't a lot of damage where it matters (i.e. internals looked OK & clean, displays unscratched, etc), and the first screen I put into my own PB170 seems to work great! Ran it for several hours and no signs of any black creep. Just out of curiosity, is the problem bound to come back eventually? I.e. are all PB170 screens "broken"? Or only some of them?

Posted by: uniserver on 2012-08-06 21:44:04 i baked my screen at 210 degrees for about an hour and it helped,(by about 40%) as talked about in other forums its moisture that has seeped into the liquid crystal. someone suggested placing just the LCD panel in a 5 gallon bucket filled with rice for a week might also do the trick.

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