I would probably try something less harsh on pots to start, not knowing what they’re made of. Try fader lube if you can get it.
Mu0n's Color Classic thread
- Thread starter Mu0n
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You can only control the background for the red (ie, there's no Red Drive), unlike the other 2 colors.:
So maybe my G2 value is at the frontier of the red not kicking in maybe?
Edit- G2 did not help. Same result I got from a few months back.
Source: https://tim.id.au/laptops/apple/legacy/color_classic.pdf
So maybe my G2 value is at the frontier of the red not kicking in maybe?
Edit- G2 did not help. Same result I got from a few months back.
Source: https://tim.id.au/laptops/apple/legacy/color_classic.pdf
Last edited:
I don't know what type Andrian's Digital Basement uses, but I have a can of the general use D5 stuff. With that said, I've never used it on POTs because I know there's a "Fader" version too:
DeoxIT Fader F Series With Shop - CAIG
DeoxIT® Fader F-Series Removes Contaminants, Lubricates & Protects Moving/Sliding Contacts and Carbon-based Controls DeoxIT® Fader F-Series is a precisi ...
caig.com
But even though DeOxit Fader mentions both "POTs" and "Faders," it could be possible they are thinking more of the big fancy POTs like the ones used in Audio equipment. @Kay K.M.Mods uses those kind of POTs in his guitar repair work, so maybe he has used DeOxit Fader?
The POTs on the CC Analog board are the tiny "normal" kind you see on many non-audio related electronics, used to adjust voltages and the like. So I don't really know if DeOxit Fader would be best for those, as opposed to DeOxit D5. Maybe both work work? It's best to ask Craig rather than guess, unless somebody like Kay chimes in with a first-hand experience. I checked reviews of DeOxit Fader on Amazon, but those folks seem to be using it on audio equipment, and one guy said it ate his silicone parts.
It would be good to figure out which flavor of DeOxit is good for the tiny POTs like those on the CC Analog board because that info will be helpful to all of us. Asking Adrian B. would be great if he would reply. But in my experience, most of the big YouTubers don't participate in the comments under their videos for some reason.
Look at the actual structure. The resistance value is determined by moving the brass terminal back and forth between the resistance band made of carbon. This is the same for the big 24mm Pots and this little variable resistor.
If dirt due to aging is the cause, the contact restorer like DeOxit is effective. But it won't fix a scratch on a carbon resistance strip, or a worn and chipped resistance strip...
In that case, it will be replaced. My CC has some Pots replaced. Some of the footprints were peeling off if it was terrible. What was peeling off was probably pushed with a wrench and a load was applied.
I appreciate the side discussion about deoxit and what should and should not be used on each type of potentiometer. I will run into that conundrum for sure one day - but it doesn't seem to be today. I know what scratchy pots feel like, but my machine doesn't suffer from it after testing them out while manipulating a live image, at least yet.
Here are my observations regarding some of the pots:
Red Background - does not affect the presence of reddish hues in the main image at all as expected, only adds a general red background in the normally black border area. Seems to work as expected.
G2 - I can increase it enough to get those horizontal scan lines (beam not being turned off when it has to go from the extreme right edge back to the extreme left edge) start to appear. I can lower it to get a decent image that doesn't bloom in intensity too much, all is as expected.
Next, I started reading only about general sony trinitron CRT advice and stumbled upon all sorts of tests to perform, with or without component replacement. One post gave me the idea to lower the green and blue drive to see if it would induce red more, and while I was starting out by manipulating the green drive first, I restored red while I was putting my screwdriver in the green pot.
Next up, the sound issue. What can definitely cause this? Remember, the bootup chime is perfect sounding. Then, it comes to this garbled state for every sound.
Here are my observations regarding some of the pots:
Red Background - does not affect the presence of reddish hues in the main image at all as expected, only adds a general red background in the normally black border area. Seems to work as expected.
G2 - I can increase it enough to get those horizontal scan lines (beam not being turned off when it has to go from the extreme right edge back to the extreme left edge) start to appear. I can lower it to get a decent image that doesn't bloom in intensity too much, all is as expected.
Next, I started reading only about general sony trinitron CRT advice and stumbled upon all sorts of tests to perform, with or without component replacement. One post gave me the idea to lower the green and blue drive to see if it would induce red more, and while I was starting out by manipulating the green drive first, I restored red while I was putting my screwdriver in the green pot.
Next up, the sound issue. What can definitely cause this? Remember, the bootup chime is perfect sounding. Then, it comes to this garbled state for every sound.
But how do you know if the carbon is worn away on the small POTs used in the Color Classic that @Mu0n is talking about?
Thought he speaker only, or through headphones too?
If it sounds the same through headphones too, I doubt it is the capacitor next to the sound chip, but has that capacitor been replaced along with all others on the analog board? Seems odd that the sound chip itself would be bad if the boot chime is perfect. If the boot chime was badly distorted too, I would suggest swapping the sound chip. But again, it doesn't seem logical it would be that. And yet, that chip is what is doing the sound generation. Hmmm...
One very sure way is to remove the Pot first. Measure the resistance with a multimeter while turning the pot. It is better to measure terminals 3 to 2.
When normal, it can be varied linearly.
If the carbon is frayed, you will see ohm disturbances.
For example, a point of several milliohms appears at a passing point. A place that is fragmentarily insulated.
And for auditory testing, you need to pass audio through. If there are scratches or abrasions, noise will be heard. In this case, pin 3 is the input and pin 2 is the output. It would be better to drop the number 1 to ground, but it is not possible with this pot because the impedance does not match. They are 22K or 10K ohms.
an idea on good sound at first, followed by bad sound:
not much has to be energized at the time of the chime sound. The screen image doesn't have to come on right away. Maybe there's badly regulated/filtered power that makes its way when Finder sound clips are played. Just a thought. I can certainly retest my 5V rail.
a new wrench:
I made my pot adjustments with the case off, got my red color back as you saw in the screenshot, then put the case back. I'm back to a few of the behaviors I got back in May:
-boots right when the switch is flicked rather than when the keyboard power button is pressed
-get a very faint image among a grayish intense background
- can see colors swap in and out with light taping around the frame near the pots, but very rarely and not reliably - might be a coincidence that's temperature/time based. Actually the power cable surrounding frame as well (though it's near so the vibrations may get to the same place)
-can get a horizontally shrunk image at 50% displaced to the left, vertical is fine.
What did I do to get back to this horrible state?
-I used pliers to curve in the bottom metal shield tabs so that they make good contact with the logic board ground loops (thinking that might solve the sound issues)
-I tried to set the analog + logic board structure and seat it as best I could towards the front of the computer so that both edge connectors are really seated in before putting in the case.
The loss of a lot of plastic material at many places inside the case, which normally ensured that there was no rotation at all of the innard structure gives me an additional challenge while I try to repeat successes.
I will test out the headphone idea when and if I get back to yesterday's state.
not much has to be energized at the time of the chime sound. The screen image doesn't have to come on right away. Maybe there's badly regulated/filtered power that makes its way when Finder sound clips are played. Just a thought. I can certainly retest my 5V rail.
a new wrench:
I made my pot adjustments with the case off, got my red color back as you saw in the screenshot, then put the case back. I'm back to a few of the behaviors I got back in May:
-boots right when the switch is flicked rather than when the keyboard power button is pressed
-get a very faint image among a grayish intense background
- can see colors swap in and out with light taping around the frame near the pots, but very rarely and not reliably - might be a coincidence that's temperature/time based. Actually the power cable surrounding frame as well (though it's near so the vibrations may get to the same place)
-can get a horizontally shrunk image at 50% displaced to the left, vertical is fine.
What did I do to get back to this horrible state?
-I used pliers to curve in the bottom metal shield tabs so that they make good contact with the logic board ground loops (thinking that might solve the sound issues)
-I tried to set the analog + logic board structure and seat it as best I could towards the front of the computer so that both edge connectors are really seated in before putting in the case.
The loss of a lot of plastic material at many places inside the case, which normally ensured that there was no rotation at all of the innard structure gives me an additional challenge while I try to repeat successes.
I will test out the headphone idea when and if I get back to yesterday's state.