Light at back of computer flashing after shut down

[kithra]

[FONT=&quot]My computer has an ASUS All Series Model (Intel) motherboard, sorry I don’t know the exact details as somebody else installed it for me a few months ago. BelArc says the main circuit board is AUSUTeK Computer Inc. H81M-PLUS Rev X.Ox. And I run Windows7 Home Premium 64-bit.[/FONT]
[FONT=&quot]I have wi-fi and an Ethernet cable and I never turn the router off, so the lights on that are normally always on, although occasionally a red light shows it’s not using the internet.[/FONT]
[FONT=&quot]For the last few days I’ve noticed a light blinking from the back of the computer after shut-down (a sort of yellowy colour). I think it may be coming from the Ethernet position, and I do have a smartphone, again rarely used but always on, so maybe it’s trying to connect to that.[/FONT]
[FONT=&quot]Not knowing exactly what’s going on, and worrying that my computer is about to die, I’ve been turning off the power to the computer completely after shutdown, although that doesn’t turn off the Ethernet connection, but it does stop the light flashing.[/FONT]
[FONT=&quot]I’ve also noticed that when the computer is on the Ethernet cable is lit ( an orange glow) where it connects into the port – something I’ve not noticed before.[/FONT]
[FONT=&quot]No new hardware of software has been installed.[/FONT]
[FONT=&quot]I read somewhere that constantly turning off the power button at the back of the computer would probably damage it in time because of the power surge each time I switch it back on.[/FONT]
[FONT=&quot]I’ve been into the Power Management settings and see that the box “Allow the computer to turn off this device to save power is checked.” And also the next box “Allow this device to wake the computer” is checked. Should I change these? I like to be able to wake up the computer when it’s been idle for a couple of hours just by hitting the space bar and/or moving the mouse.[/FONT]
[FONT=&quot]So, my question is if what’s going on is normal, or a sign of some problem? And, if it’s normal, then is it OK to leave it just as shut down without having to turn the power off completely?[/FONT]
[FONT=&quot]I’ll be back tomorrow to see if anyone has been able to help. Thank you.[/FONT]

 

[mrjimphelps]

If the computer is on, and if there is a live Ethernet cable plugged into the computer, then it is normal to see some flicker with the two Ethernet lights. When you are logged onto Windows, the blinking should be random. When you are logged off of Windows, there can still be some blinking.

I leave my computer on all the time, unless I am going out of town for a few days. Not only is it more convenient to have it on and ready at all times, but also I believe it is less stressful on the computer than to turn it off and on. Many people would disagree with me about this.

Uncheck the box which allows the computer to shut off the Ethernet card. You need to leave the card on all the time. In this way you will never have a connection problem caused by the computer shutting the card off. And I would not allow the device to wake up the computer. Of course, if you leave your computer on all the time, this setting is meaningless.

 

[iko22]

Its a job to know where this light is happening; where you say at the back of the computer, do you mean inside the case and at the back or do you mean outside the case at the rear?

If you are referring to the Ethernet connection at the rear of the computer, then this yellow (or amber) light can mean the speed of the Ethernet. A constant amber light could well mean that the device has found a 1 Gbps Ethernet connection, whereas a flashing amber light could mean that the Ethernet controller has only found a 10 - 100 Mbps connection.

This would explain your situation quite well. If you have powered down the computer, then the device is telling you that it has lost the 1 Gbps connection.

One way to find out if this it true, is to switch off the router and then power up the computer. With the computer powered up check the light source again and make note of what you see. Then power down the computer and check what changes happen, if any.

This could well determine for you what the blinking light is telling you.

 

[Megahertz07]

All computers that I have there are 2 leds beside the RJ connector.
When the computer is on, it's normal to have them blinking.
When you turn off windows, the MB remains with 5V and power USB and the LAN ports.
As the router remains on, there is some attempt to communicate with the computer, and that is why the led blinks, even if the computer is off.

My suggestion is to do what you're doing now, a physical (switch) shutdown when not in use.
Every power line has spikes due to switch high power loads. Not to mention lightning discharges that can blow out all electronic device on "standby mode" (like a computer).

 

[kithra]

[FONT=&quot]Thank you for the replies. And sorry, I should have said that the flashing light is coming from inside the rear of the case. Thanks for the explanation about the Ethernet connection speed in relation to the lights. During the day, when the computer is on, the Ethernet shows a constant amber light. It’s only at night, after dark, when the computer is shut down that I notice the light has begun flashing.[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Sorry, but I don’t know what the RJ-45 is, and the only blinking lights I have when the computer is on are those on the router, and the one at the front showing that the computer is working.[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]As for power spikes I run the computer and all peripherals on a surge protector.[/FONT]

 

[iko22]

The RJ-45 is the standard regarding the Ethernet connector. You say the flashing light is not to do with the Ethernet port, and you say that the light is within the computer itself. More and more mysterious ...

The light only begins to flash when the computer is shutdown.

 

[Megahertz07]

As the MB remains with 5 V on standby mode, the memory also remains "on". To prevent people to insert / remove the memory in this condition, some MB has a led just to remember that the MB is "on".
You should read your MB manual. Page 1-19
http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/H81M-PLUS/E8448_H81M-PLUS.pdf

 

[Barman58]

It is very unusual these days to have the motherboard completely shut down unless the Mains supply is totally disconnected Either switched or Physically. One of the main reasons for this is that the ON-Off switch is actually a Low Voltage/Current, momentary Relay operated by the switch, which then completes the main power circuit to the rest of the components, It can also allow a Soft Start for some vulnerable components to increase the MTBF, "Mean Time Between Failure" this requires a small voltage to be present and often includes a LED to inform that mains is connected correctly.

Without this system setup certain features would not work, such as the ability to shut down the computer by software control, (The shutdown button on the Start menu), or to wake the computer remotely, (WOL-Wake on LAN). In the case of laptops it also allows the shutdown when you close the Lid.

There are other technical reasons that some systems have this ability, and you may often see the instruction for low level maintenance to allow disconnect the power and allow the system to settle for thirty seconds to allow any capacitors to dissipate before working on the motherboard. (sometimes on systems you can see this as when you pull the power cable it will take a few moments for the indicator LED to go out showing that all residual charge has left the capacitors.

Basically, all this means that there is no need to be concerned if your system has this function and indicator. Most top end motherboards will mention the system in the user manual, but not all

 

[iko22]

As the MB remains with 5 V on standby mode, the memory also remains "on". To prevent people to insert / remove the memory in this condition, some MB has a led just to remember that the MB is "on".
You should read your MB manual. Page 1-19
http://dlcdnet.asus.com/pub/ASUS/mb/LGA1150/H81M-PLUS/E8448_H81M-PLUS.pdf

It is very unusual these days to have the motherboard completely shut down unless the Mains supply is totally disconnected Either switched or Physically. One of the main reasons for this is that the ON-Off switch is actually a Low Voltage/Current, momentary Relay operated by the switch, which then completes the main power circuit to the rest of the components, It can also allow a Soft Start for some vulnerable components to increase the MTBF, "Mean Time Between Failure" this requires a small voltage to be present and often includes a LED to inform that mains is connected correctly.

Without this system setup certain features would not work, such as the ability to shut down the computer by software control, (The shutdown button on the Start menu), or to wake the computer remotely, (WOL-Wake on LAN). In the case of laptops it also allows the shutdown when you close the Lid.

There are other technical reasons that some systems have this ability, and you may often see the instruction for low level maintenance to allow disconnect the power and allow the system to settle for thirty seconds to allow any capacitors to dissipate before working on the motherboard. (sometimes on systems you can see this as when you pull the power cable it will take a few moments for the indicator LED to go out showing that all residual charge has left the capacitors.

Basically, all this means that there is no need to be concerned if your system has this function and indicator. Most top end motherboards will mention the system in the user manual, but not all

Yes, I have searched the manual pdf. There is one LED on motherboard - Standby Power LED page 1-19 - and this is Green. Then there is the RJ-45 LAN port LED indicators page 1-12 at the rear panel connector. There is no other LED lights documented in the manual. OP reports a Yellow light inside the case.

 

[kithra]

[FONT=&quot]Thanks for the further replies, and No, I said the light is probably to do with the Ethernet port, and yes, it is coming from within the computer.[/FONT]
[FONT=&quot]I’m not sure I have a network hub as it’s just a home desktop computer with the monitor, router, speakers, and printer connected. I don’t think it’s part of a LAN either as it’s just me, no other computers or other devices connected in any way.[/FONT]
[FONT=&quot]I did read the .pdf link but not sure I totally understood what it was saying. Sorry, I’m a senior citizen and things aren’t as clear as they used to be.[/FONT]
[FONT=&quot]The flashing amber (yellowy) light only began to start doing this about a week ago. The MB was installed as part of a partial re-build about 6 months ago and I haven’t noticed it before this. When I first noticed it happening I thought it might be to do with dissipating capacitor residue. But it went on and on so I switched it off totally via the power on/off switch at the back of the computer. And I’ve been doing that ever since.[/FONT]

 

[iko22]

Apologies, and my bad! I misunderstood you about the Ethernet light.

In that case, it is highly likely it is one of the two Ethernet lights, as I cannot see any more yellow lights described in the user manual. Only thing, it is strange that you had not noticed this earlier than a week ago.

Perhaps you would like to check this. As I suggested in my earlier post, you can power off the router before switching the computer down. Does the yellow light come on when there is no router present?

Alternatively. If you want. You can take the computer case lid off and photograph the location of the light, and upload your photograph to this forum, via the attachment paperclip, and we could look at the photo for you. If you wish.

If it were storage capacitance it would have dissipated within 40 seconds or so. So, maybe you need to wait a little and check again for the flashing light?

 

[kithra]

[FONT=&quot]No need to apologise, but thanks anyway. I couldn’t see any more lights in the manual either, but I find it really odd that it’s only just started happening. I’ll try what you suggest about powering down the router and see if it makes any difference. Thanks for the suggestion. But as for taking the case off and taking a photo I’m afraid that’s just too much for me as it’s a big case, and my hands no longer have the strength to deal with moving it. I’ve also noticed that the light doesn’t start flashing right after the shutdown but only a few hours later. All very odd.[/FONT]

 

[kithra]

I took your advice and turned off the router before powering down the computer last night. It worked, there were no lights flashing at all. So, while that solved the problem does it mean I should turn off the router every night?

 

[iko22]

So, while that solved the problem does it mean I should turn off the router every night?

That is great news. I should think it would be a good suggestion to turn of all electronic sources at night, just to reduce the carbon footprint.

I have all devices, (my computer, monitor, speakers and router) attached to the same surge protected extension cable, then at the end of the day, I just switch the extension cable off at the wall socket. This then turns off all four connected devices at once.

If the setup you have does not allow, or the wall socket is unreachable, then a good suggestion would be to try a remote controlled mains socket.

Examples here: Remote controlled mains socket

 

[kithra]

I too have all my devices plugged into a surge protector, but I can't turn it off at night because my landline scam phone is also connected to the extension cable. And, if that is turned off my phone doesn't work. But thanks for the link to remote controlled mains sockets. I hadn't heard of those before.

 

[Barman58]

I've gone a different way on the Carbon footprint situation, my systems are left on overnight, Monitors (or Screens), in low power mode or off depending on the device type. This means that all those background tasks that are essential for smooth operation can take place overnight - Backups, maintenance sweeps, updates all occur at night.

The carbon footprint is offset by fitting LED low power lighting everywhere, and external lighting units are solar powered LED devices

The router is fed through a battery backed APC UPS system that also powers an Uplighter (LED of Course), and the Base unit for my cordless Phones. This gives power to call emergency services if needed (the base unit has to be in operation to make a phone call to 999 although the phone circuits are powered remotely at the exchange, and landline phones are locatable by the operator even if vocal communication is impossible )