Evidence Suggests Blue Light Inhibits Sleep Mac OS

• Evidence Suggests Blue Light Inhibits Sleep Mac Os X
• Evidence Suggests Blue Light Inhibits Sleep Mac Os X
• Evidence Suggests Blue Light Inhibits Sleep Mac Os 11
• Evidence Suggests Blue Light Inhibits Sleep Mac Os V

Close lid and let the Mac Sleep – Open Lid = KP; Apple Icon to Sleep – Hit key or move mouse = KP; The KP can happen with the MacBook Pro Plugged into Power or not. KP Can also happen while connected to a Dock or Monitor. Panic Report for 10.15.5 Beta 1 (19F53f). Researchers are continually releasing studies on the potential harm of blue light. When you stare at a screen all day and into the evening, it can affect your sleep and disrupt your body's natural. 4.3 Mac OS - - Just for the record, getting this game to run under OS X was easily the most aggravating thing I have done in recent memory. Not because the game itself is hard to get running really, but because of various problems I had to resolve on my own setup to get everything in order.

Most of the Time its is alway the PMU RESET Button. it always works (except for the one bondie, but that was the power supply) its very tiny and does the same thing as removing the clck battery, ust its not a likely to kill the battery.

this was a problem with your 'PMU'.
occurs freqently when there is a power disruption in your area.
there is also a small button on the logic board that would do the same thing.

On my machine, at least, this is called the 'CUDA switch.' Search Apple help for more information. Reportedly, pushing it more than one in a power cycle will render your computer useless!

I have a G4 Quicksilver 2002 that almost never powers up from a cold start -- I always have to open it up and hit the CUDA switch. From what I've read, it's a problem with the logic board or the power switch board, and would have been replaced under warranty had the problem shown up soon enough.

Try a new clock/PRAM battery--you can get them at Radio Shack.
If that doesn't fix it, it may be a problem with the front panel circuit board.

Yes, I had this same thing happen on my mirrored door G4. And I found the same solution. All I did was put a new battery in. Thanks for posting this.
I think there was something on the Apple website about it recently - something to do with the battery draining because of some power surge or improper shutdown.
---
soph

I have rescued dozens of G4's with this symptom by simply unplugging the power cord, removing the battery, counting to 10, reinserting the battery and power cord - and booting.

It's a good idea to always check the voltage on the battery because of the discharge curve on Lithium ion batteries. The drop off is rather steep as compared to a alkaline type which drops off gradually. Since the motherboard doesn't draw that much power, simply warming it up will often do the trick (ie. like your remote control for the TV).

I hope you don't mean warming up the battery. You don't want to warm up a lithium ion battery. Just google what could happen if you do that.

Evidence Suggests Blue Light Inhibits Sleep Mac Os X

Actually, you want to measure the battery's voltage and its current--lithium batteries (at least the 3.6 volt, 1/2 AA batteries used to power Mac clock/RAM chips) will maintain their rated voltage even after they've practically drained away, but their current level will tell the true story; they won't measure substantially less than their rated voltage until some time after they're no longer useful. What's happened is the battery's chemicals have changed state, to the point where the battery is basically a big resistor and so they can't deliver enough current, though the voltage deceptively still looks OK. Unfortunately, many cheap digital meters don't have a current measuring scale.

i do the same thing, w/o removing the battery. i unplug the pwr cord and click the start button to discharge the pwr supply.

Now you tell me! I took my dead MDD to the Genius Bar and the genius told me the odds were 99% that it was the logic board! I junked the machine! My symptoms were exactly what you described! Aaargh!

The geniuses really aren't.
This was a simple PMU issue. There's no reason to waste your time with pulling the battery out. Just push the button on the logic board.
ACSA 10.3, ACTC 10.3, ACHDS 10.3, ACDT, ACPT

Resetting the CUDA, PMU or SMU for power related issues is such a basic step that I find it hard to believe that ACHDS, ACDT and ACPT certified techs (which is what Geniuses are) would not have tried that.
There probably was a logic board issue after all.

I found it hard to believe myself, but it's what happened. I subsequently managed to retrieve the machine and reset the PMU - now it works fine. There was nothing wrong with the logic board.

Resetting the Power Manager for a none starting Mac is a standard procedure and is fully documented on apple knowledgebase. I not sure why it appears as a hint on this in 2005. When Mac users have been using the technique for years.
What is important to know is that you must neve reset the PMU button twice in a row. You must leave at least 10 to 15 seconds if you think you need to press it again. If you do press the button twice you can crash the PMU which would cause the batttery which normally last for years to expire in 3 days.

As well as keep your machine from ever booting again without replacing the logic board.
robg, PLEASE, post the instructions for a proper PMU reset procedure for desktop machines in the displayed text of any hints that get close to this subject. They are:
1. Unlpug the power cord.
2. Using a non-metalic tool (your finger, if it'll reach) push the PMU reset button (location varies by machine) ONCE and for no more than one second.
3. Wait 15-60 seconds.
4. Plug the power cord back in and hit the power button.
Note that a bad logic board, processor or stick of RAM can cause the same symptoms described by the original poster so a PMU reset is no guarantee.
'I'm never quite so stupid as when I'm being smart.' -Schultz

I don't know where the myth came from that suggests if you crash your PMU you need to replace your logic board but it's not true.
The most you can do crashing PMU is to expire the battery.
For those that want the official procedure for resetting the PMU here it is.
Resetting the PMU on the Logic Board
The PMU (Power Management Unit) is a microcontroller chip that controls all power
functions for this computer. The PMU is a computer within a computer. Its function is to:
• tell the computer to turn on, turn off, sleep, wake, idle, etc.
• manage system resets from various commands.
• maintain parameter RAM (PRAM).
• manage the real-time clock.
Important:
Be very careful when handling the logic board. The PMU is very sensitive and
touching the circuitry on the logic board can cause the PMU to crash. If the PMU crashes
and is not reset, the battery life goes from about five years to about two days.
Note:
For the location of the PMU reset button, see 'Logic Board Diagram' in the Views
chapter.
Many system problems can be resolved by resetting the PMU chip. When you have a
computer that fails to power up, follow this procedure before replacing any modules:
1. Disconnect the power cord and check the battery in the battery holder. The battery
should read 3.3 to 3.7 volts. If the battery is bad, replace it, wait ten seconds, and then
proceed to step 2. If the battery is good, go directly to step 2.
2. Press the PMU reset button once and then proceed to step 3. Do not press the PMU
reset button a second time because it could crash the PMU chip.
3. Wait ten seconds before connecting the power cord and powering on the computer. If
the computer does not power on, there is something else wrong with it; refer to the
'System' section of 'Symptom Charts' in this chapter.
Note:
The above procedure resets the computer's PRAM. After resetting the PMU, be
sure to reset the time, date, and other system parameter settings.

I have had a number of clients with un-revivable logic boards who've told me that before bringing their machines in for service, someone they knew told them to either hit the PMU reset button several times in a row or even to hold it down for thirty seconds or more. Granted, this is just a correlation and not a proven cause and effect - more likely these folks may have just had an ESD incident while they were dinking around inside their machines or the MLBs had already failed in some other way - but why take chances? If a little fear causes people to be conservative and extra careful when messing around with a part that's US$300-500 to replace, that's less harmful misinformation than the many and varied PMU reset procedures that get propagated here and other places on the web. BTW, thanks for posting the official procedure.
(Note: Apple appears to be dispensing with the PMU - the newest G5s have a SMU (System Management Unit) which handles most of the same tasks but does not have a reset button. It's reset by simply unplugging the power cord for 15 seconds. I would hazard a guess that Apple may be tired of all the warranty logic board replacements that they've done because the user did an improper PMU reset.)

PMU reset and/or battery removal can fix many problems.
Here is another hint:
On some Macs (like the G5 iMacs) actual REMOVAL of the battery can be difficult. A workaround is to get a small piece of paper (something which is a bit stiffer than normal paper works best like a matchbook, index card, etc.) and just slip this under the top battery contact. This effectively disconnects the battery.
Wait a good 10-15 minutes, then remove the paper, and start up.

this is a known issue with the G4 MDD models. if you browse through apple's discussion forums, you'll find plenty of evidence of this.
i support a newspaper's Macs and have had this problem with many of the MDD units. we purchased about 50 or 60 of them in 2002, and probably half of them have had this PMU problem at one time or another.
this is the one model where i've experienced this problem most often. most other newer or older Macs might need an occasional PMU reset, but not the MDD models.

This is a copy of an email I sent in response to a mailing-list posting about a system that sometimes spontaneously re-boots after being shut down and sometimes won't boot when the power button is pressed (it was a MDD PowerMac). My (edited) response to the poster was:
-----
Your problems might be related to the following:
It turns out that some of the ATI Radeon graphics cards (e.g., the 9000 in our ol' DualGig MDD) can cause/exhibit these problems when using the DVI-to-VGA adapter with certain kinds of VGA cables. VGA cables have some pins that are either present/wired or not because they are used to indicate the 'kind'/size of montior (VGA, XVGA, etc. . i.e., the pixel dimensions).
I've found that using some VGA cables (i.e., wired to indicate some monitor sizes), but not others, will cause the following behavior (sorry, I've not figured which is which):
- when the VGA cable is connected and you attempt to shut the system down, the system will shutdown then immediately reboot (i.e., seemingly can't be shut down)
- when the system is powered down (e.g., by removing the A/C power cord) and then the power button is pressed (while the VGA cable is connected via the DVI-to-VGA adapter) the system will not not start up until the VGA cable is temporarily removed
One can imagine why this scenario occurs when you consider that the ATI card must (somehow) be connected to the power-on logic/signals because it also has an ADC connector (that supports powering on/off the system via an Apple monitor).
Anyway, I hope this helps someone . sometime.
(Great resource, this Mac OS X Hints . nice job!)

I bought a used G4 Quicksilver at auction. It looks in great shape, no damage, cracks or signs of misuse. Anyway I have no luck in getting it to power up. The Front panel light will not stay lit, but the fan is running and the little red light on the mother board is lit. The DVD/CD drive clicks quietly twice on start up but other than that there is no activity. I replaced the battery and used the info you guys posted about the power button located on the board also, but still no luck. Any other suggestions? Thanks.

I have to to the same thing to power up my cube, the only problem is that it only works once. Glidch mac os. After turning the power off I have to redo the hole procedure to start it up again. (and everytime I have to remove the graphicscard to get to the reset button)
Any ideas what else I could do? (buying a new battery didn't work either)

The following check list is from the cube engineers manual. As you can see everything points towords replacing your logic board if yoru rule out issues with the power supply, dc-dc Board etc.
If have resetting your PMU your still getting issues and you've followed the procedure here, then I would use the hard ware test cd that came with your cube which will test your logic board. You would also get much more advice about your issue over at the disussion forum at http://cubeowner.com.
No apparent power (no sound and power LED is not lit)
1. Verify the power outlet is good.
2. Replace the power cord.
3. Reset the logic board. Refer to 'Resetting the PMU on the Logic Board' in this
chapter.
4. Check for trickle voltage on the power adapter connector. Refer to 'Power Adapter
Verification' in this chapter. If verification fails, replace the power adapter.
5. Disconnect external devices, including the monitor, and start up the computer.
6. Remove internal cards and start up the computer.
7. Disconnect internal hard drives from the logic board and start up the computer.
8. Reseat the DC-to-DC board in its connector.
9. Check the modem connector. If the connector has any bent pins, replace the logic
board.
10. Replace the logic board.

Like a lot of Americans, Amalie Drury has grown very attached to her smartphone.

The 33-year-old Chicago writer checks the device multiple times a day for Facebook updates and email messages. She brings it into the bathroom when she brushes her teeth. And she often totes it to bed, 'just to check email one more time and play a few more rounds of Words With Friends.'

If Drury wakes up in the middle of the night, she reaches for her phone again. 'My first thought is to pick up the iPhone to see what's happening in the news,' she said. 'I'll . sometimes read long features and not really be able to go back to sleep.'

Drury's 'terrible habits,' as she calls them, reflect those of millions who bring their phones, tablets, e-readers and laptops to bed each night, according to consumer research. The trend is causing increasing concern in the medical community based on mounting evidence that the type of light produced by our portable electronic screens can contribute to sleep loss.

Last month the American Medical Association issued a policy recognizing 'that exposure to excessive light at night, including extended use of various electronic media, can disrupt sleep or exacerbate sleep disorders, especially in children and adolescents.'

Any light at night can be disruptive, researchers say, but in recent years studies have zeroed in on the particularly potent 'blue light' emitted abundantly from the energy-efficient screens of smartphones and computers as well as many energy-saving fluorescent bulbs.

Because blue light is especially prominent in daylight, our bodies associate it with daytime, which may be why exposure to blue light can make us more alert and improve our response times. It also has been shown to suppress melatonin, a hormone that helps regulate sleep and is not produced during the day.

In May 2011, Swiss researchers at the University of Basel reported that subjects who spent time at night in front of an LED computer screen, as opposed to a screen emitting a variety of colors but little blue light, experienced 'a significant suppression of the evening rise in endogenous melatonin and … sleepiness.'

https://softwaresenior.mystrikingly.com/blog/translatium-10-2-1-powerful-translation-app-for-macos. Over the last decade, neuroscientists have discovered novel light-sensitive cells in the eye that detect light. These cells are separate from those we use for vision and contain a photopigment called melanopsin that is particularly sensitive to blue light. Scientists think this light-detecting mechanism, which regulates our sense of night and day and time of year, evolved before the ability to see.

'Blue light preferentially alerts the brain, suppresses the melatonin and shifts your body clock all at the same time,' said Harvard Medical School sleep researcher Steven Lockley. 'Your brain is more alert now and thinks it's daytime because we have evolved to only see bright light during the day.'

Compounding the problem, Lockley and others said, is that unlike TV (which also emits blue light), these newer electronic screens are positioned close to our faces, increasing the intensity and effects of the blue light on our brains.

'The closer you have a light source to the face, the more intense it is,' said Lockley, co-author of 'Sleep: A Very Short Introduction.' 'And the further you go away, it falls off quite quickly. So having things close to the face is much worse than having a TV that's 10 feet away.'

The researcher stressed that these types of screens are not all bad. When used during the day, they can help stabilize circadian rhythms and increase alertness and reaction time.

Increasingly, however, consumers are using devices that emit blue light well into the night. A recent poll by Rosetta marketing consultants indicated that today almost 1 in 3 Americans who use the Internet own a tablet and that 68 percent of them report taking the device to bed.

While tablet manufacturers remain generally quiet about the blue light issue — neither Barnes & Noble, which makes the Nook Simple Touch with GlowLight, nor Amazon, maker of the Kindle Fire, responded to requests for interviews — industry watchers and scientists confirm that some manufacturers are already developing new features to automatically modulate or remove blue light emissions at night.

Noveen mac os. Representatives of Apple note that blue light emissions can be reduced on the iPad by adjusting brightness and switching to white on black mode at night through the 'settings' feature.

Other companies also are working on technical solutions. In 2005, after conducting early studies on the effects of blue light on sleep, researchers at John Carroll University in Ohio formed a spinoff company called Photonic Developments to market products that can mitigate blue light exposure. These include orange-tinted glasses, screen filters and blue-light-free bulbs, all sold at LowBlueLights.com.

'We have many people talking about the problem,' said Richard Hansler, one of the scientists who developed the products, 'but I'm surprised that so few have come up with solutions for it.'

There is also a free computer program called f.lux — downloadable at stereopsis.com/flux — that reduces the levels of blue light coming from a computer screen later in the day.

Many people who use electronic media in bed told the Tribune they had trouble sleeping or suffered from insomnia, but others felt that streaming a sitcom, reading an e-book (especially in white letters on a black screen) or perusing Facebook relaxed them and could even put them to sleep.

Sheri Jacobs, who runs a marketing firm in Deerfield, is in the second group. Jacobs said she uses electronic devices mostly for entertainment and reading later in the evening, leaving email and other work-related tasks for the morning.

'I'm a great sleeper, probably because I run in the early morning and I'm exhausted by bedtime,' Jacobs said. 'I've heard about (concerns over electronic light at night) and so my approach has been to disconnect from the email at a certain point and use it for fun things like reading or watching videos.'

Dr. Alon Avidan, who directs the Neurology Clinic at UCLA, recommends good sleep habits — bright days, dark nights — to everyone but says some people are genetically much more sensitive than others to the effects of light exposure.

'Some patients will watch TV and do computer work late at night and not suffer from insomnia or other problems,' he said. 'But other people have what's called hyperarousal. They can't go to bed without reading email, and then they have a hard time shutting their mind off. Those are the patients for whom light exposure is having a greater impact and who are genetically more likely to be affected.'

He also notes that electronic media exposure is rarely the sole culprit in sleep problems.

'There are often many other factors involved such as stress, anxiety and sometimes restless leg syndrome,' Avidan said. 'So it's hard to say that the electronics are purely at fault, but they certainly aren't making things any better.'

While it's clear that light exposure can delay sleep initiation, it's still unclear whether it can contribute to sleeplessness in the middle of the night. Also unclear are the exact light intensities that will trigger sleep disruption and whether adolescents respond to light exposure in the same way that adults do. The AMA and others have recommended further research into this still-young field.

Evidence Suggests Blue Light Inhibits Sleep Mac Os X

Drury, the late-night iPhone user, said she's intent on changing her ways 'out of courtesy to my fiance,' among other motivations.

'I have always been a pretty calm and focused person,' she said. 'But I am feeling a little adult ADD about this, and I want my brain to slow down.'

For others, even those with trouble sleeping, removing the electronic screens from the bedroom will be a harder transition. The devices have simply become part of their life.

Heaven on Seven chef Jimmy Bannos said he keeps smartphones and an iPad with him at all times, including on his bedside table next to his sleep apnea machine.

'It's for relaxation and staying in touch,' he said. 'When I wake up in the middle of the night, I'll take a look at them, check my email, see what's happening in the restaurants and even do some Internet banking. I also like to go on Facebook to see whose birthday it is and wish them a happy birthday.'

Bannos said he follows a lot of good sleep practices, including using blackout curtains, a white-noise fan and even a sleep mask. So would he ever take the next step and consider removing the blue-light devices from his bedroom?

Evidence Suggests Blue Light Inhibits Sleep Mac Os 11

'No,' he said, echoing the sentiments of many who don't want to give up this part of their nightly routine. 'Never.'

Evidence Suggests Blue Light Inhibits Sleep Mac Os V

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