PowerBook 165c DISPLAY QUESTIONS

[JDW]

This question is for you experts out there, and that includes @Ron's Computer Videos & @Mac84 & @techknight . Because the display is Passive Matrix, is ghosting normal, or is it showing only because the stock caps inside the display haven't been changed? You can more easily see what I mean in my short video below...

Note at the end I show very slight yellowing at all 4 edges, and I'm curious about that too.

Looking forward to hearing your expert opinions!

 

[Yoda]

I'm no expert, but the ghosting in your video looks marginally worse than as-new, but not by a whole lot. I'd expect the display to need a recap by now anyway, but as they deteriorate, the most typical symptom is that the brightness/contrast isn't stable at power-up, and takes a minute or so to settle - and over time the ghosting effects get worse, of course, showing vertically from 'contrasty' edges, as in your video. At extremes, I have seen passive matrix screens 'throb', but I think by that point, a recap would be long overdue!

The colour passive matrix screen in the 165c don't seem quite as prone to ghosting as the caps deteriorate as the greyscale screens were, and yours looks a fraction better than either of my 165c screens, but I've seen a lot worse.

Not sure about the yellowing - neither of my 165c machines show any sign of that.

 

[JDW]

Thank you for the feedback.

It certainly doesn’t take a minute or even close to that for the screen to “settle“ at cold boot.

There is no “throbbing“ either, and the flicker you see in my video was simply my camera not being synced with the LCDs refresh rate. Later in the video, I better sync it to the camera, but not perfectly.

It’s interesting that you suggested these passive matrix machines produced ghosting even when new back in the day because if I had purchased one back in the day and saw that, I would’ve been pretty surprised in light of the computers price. But maybe most people back then weren’t surprised just because the technology was quite crude? I was heavily into desktop Macs back in those days so I never saw a Powerook screen in person back then.

Anyway, in regards to recapping, I started a separate thread about that yesterday, at the link below. No one has replied to that yet, probably because no one knows if super low ESR Polymer caps would work well inside the LCD unit versus leak-prone electrolytic types. Low ESR is a good a lot of the time but not all of the time. It depends on what the caps are supposed to do in a given circuit.

https://tinkerdifferent.com/threads/powerbook-165c-recapping-list.5321/

 

[akator]

What I'm seeing in your video is how I remember these things looking when new (or close to it) back in the mid 90s. As @Yoda mentioned, yours doesn't look too bad. That's just how passive matrix displays were, even on handhelds like the Sega Game Gear and Sega Nomad. I've got a few recapped passive matrix displays and they all show those characteristics, some more than others, but still there.

I found it was something I could mostly live with back in the day for everything except gaming. Try playing Apeiron on a passive matrix display and the ghosting makes things very difficult.

Also back then we would ask the question, "Is getting rid of passive matrix characteristics worth an extra $3K?"

 

[JDW]

…back then we would ask the question, "Is getting rid of passive matrix characteristics worth an extra $3K?"

For Mac lovers who needed a portable, I guess. But my solution to save money and maximize performance in those days was to just stick to desktops.

Anyway, thank you very much for the excellent info because you answered my question perfectly!