imactheknife
Well-known member
right. so no contrast slider either. Just non backlit. Ok, makes sense.
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So, I bought a portable…
- Thread starter imactheknife
- Start date
3lectr1cPPC
Well-known member
Yeah, it's still TFT Active Matrix so it doesn't need contrast adjustment.
LaPorta
Well-known member
I was just basing this on your video showing the slider doing nothing. The above is correct, there is no “brightness” adjustment on the Portable…just contrast. That is all. The fact that your contrast slider doesn’t do anything…I thought that was your issue and thought that newer control panel might not be working properly. No idea why your contrast slider, with the correct control panel I sent you, doesn’t adjust contrast.
LaPorta
Well-known member
The Portable does have contrast adjustment. It works the way it should on my non-backlit.
3lectr1cPPC
Well-known member
Oh. Didn't know that! Good to know.
imactheknife
Well-known member
Yeah is it a big change? Or subtle change in contrast?
LaPorta
Well-known member
Give me a bit to get mine out of mothballs, and I will show you the difference.
desertrout
Well-known member
@imactheknife On mine it's very noticeable, the lowest end of the slider makes the display quite faint. FWIW I did see a difference in your video, but it was very minor - certainly should be more.
imactheknife
Well-known member
Interesting, well i wish i knew if i had proper version of 6.0.7 on it, or of there is a more specific version for portable?? When i installed a chose under customization to do portable etc. i wish i had more memory lol.. maybe system 7 would be better??
desertrout
Well-known member
I have doubts 7 would make a difference, and likely will drag without enough RAM. I'm using 6.0.8, seems good. This might merit a look at some docs to see how the contrast is being controlled... I'm not sure what the control panel is doing exactly, but it might be discoverable looking at tech notes and the schematics.
imactheknife
Well-known member
Would it be something on logic or lcd? It is recApped etc and working excellent otherwise
desertrout
Well-known member
I honestly don't know - I'm not familiar with the LCD circuitry. There *are* caps on the panel but they're not so prone to leakage as on the 1xx PBs afaik. Others have recapped their Portable screens, but I'm not sure if it was to address contrast issues. I wish I could provide more certainty here. I can take a look at some docs later and see if anything becomes apparent.
desertrout
Well-known member
So, the dev notes (https://cdn.preterhuman.net/texts/computing/apple_hardware_devnotes/Portable.pdf) describe the contrast control as a pwm signal from the Power Manager which is run through an rc network.
Here's the network in question:
I'd do an inspection around those components (which are over by the right-side keyboard connector), maybe some testing and extra cleaning. Possible there's some lingering electrolyte from C14 and C116 mucking things up.
Here's the network in question:
I'd do an inspection around those components (which are over by the right-side keyboard connector), maybe some testing and extra cleaning. Possible there's some lingering electrolyte from C14 and C116 mucking things up.
imactheknife
Well-known member
No,,haven’t been back into it lately. Will have to take a closer look and see. Was hoping to get more memory for it but someone out bid on sleeze bay lol..
imactheknife
Well-known member
I just have the 1 meg on logic board
