Weird Wi-Fi connection problem

[sacentre]

Can anyone suggest what could be causing this? In 30 years of experience building and troubleshooting PCs, I haven't seen or heard of this issue before.

Just yesterday, my wife's Windows 10 desktop PC AND her Android phone stopped detecting our Wi-Fi access point . (The Wi-Fi router is only about 8 feet away in the same room). The weird thing is that when I check available networks, both devices can "see" all my neighbours' networks in our block - just NOT ours. Her phone works normally at all the outside Wi-Fi spots we go to like cafes etc. My own two Windows 11 desktop PCs, my HP tablet as well as my Android phone all connect as normal. I've made no changes to hardware or software or any config changes that might explain it. I tried rebooting the router, and changing the Wi-Fi adapter in her PC to a USB Wi-Fi dongle - same result and this still wouldn't explain why this is also happening with her Android phone.

It doesn't seem like a hardware issue so that leaves software and I'm wondering if it could be caused by a virus or malware. I can't think of anything else that might block 2 devices from seeing a single Wi-Fi network.

I'd be grateful for any suggestions.

TIA
Trevor

 

[Bill_Bright]

I don't see how this could be malware affecting just 2 devices, and 2 different devices (Windows and Android) at the same time, but not the other devices in the house using the same router.

This is odd. Just thinking out loud... ...I wonder if your router experienced a system reset or some sort of corruption. I note I have a couple devices that must see the SSID in order to connect automatically. Is your router broadcasting the SSID of your wifi networks (2.4GHz and 5GHz)?

Are her two devices located in the same area? And are other devices in that area connecting fine? I'm thinking of a possible interference issue where some nearby device (like a microwave oven or communications tower, or big TV or some other device) is emitting excessive amounts of EMI/RFI, interfering with her signals. Or perhaps a large metallic object (big metal file cabinet or refrigerator) blocking the signal.

I would also power cycle her two devices and with the PC, do a "cold" reboot. By “cold”, I mean shut down the computer and flip the master power switch on the back of the power supply (if the supply has one) to off (or “O”), or unplug the power supply from the wall for about 15 seconds. Then turn the master power switch to on (or “|”), or reconnect the power cable and boot up and see what happens. By totally removing power, you reset the PSU. It also removes the +5Vsb standby voltage all ATX Form Factor power supplies are required to supply whenever the power supply is plugged into the wall and (if applicable) the master power switch is set to on. This standby voltage is distributed throughout several points on the motherboard, including RAM for faster boots and the USB ports too. This also keeps alive several features, including “wake on keyboard” and “wake on mouse”, and the network interface for “Wake on LAN” commands. A cold reboot ensures any device settings that may be held by the standby voltage are released, then reset when power is restored. A cold reboot also helps ensure any corrupt software settings after installs and upgrades are reset too.

Keep us posted.

 

[Predictable]

Strange, but just jumping in to suggest something that popped in my mind: Considering that both devices belong to the same person, is she using any particular software or app on both of those devices that you are not on any of yours?

Strange, but just jumping in to suggest something that popped in my mind: Considering that both devices belong to the same person, is she using any particular software or app on both of those devices that you are not on any of yours?

Additionally, and you said you made no changes, but can you be sure that those two devices are not blocked via the router settings?

 

[P4-630]

Did you try "forget" or removing the network from the devices, and try reconnecting again.

 

[sacentre]

I don't see how this could be malware affecting just 2 devices, and 2 different devices (Windows and Android) at the same time, but not the other devices in the house using the same router.
I had the same thought
This is odd. Just thinking out loud... ...I wonder if your router experienced a system reset or some sort of corruption. I note I have a couple devices that must see the SSID in order to connect automatically. Is your router broadcasting the SSID of your wifi networks (2.4GHz and 5GHz)? Yes it is.

Are her two devices located in the same area? Yes And are other devices in that area connecting fine? Yes I'm thinking of a possible interference issue where some nearby device (like a microwave oven or communications tower, or big TV or some other device) is emitting excessive amounts of EMI/RFI, interfering with her signals. Or perhaps a large metallic object (big metal file cabinet or refrigerator) blocking the signal. Nothing in our apartment has changed or been added recently. I can't speak for my external surroundings. There's a huge construction site not far away with excavators and huge cranes but all work stops around 6:00 pm each day.

I would also power cycle her two devices and with the PC, do a "cold" reboot. By “cold”, I mean shut down the computer and flip the master power switch on the back of the power supply (if the supply has one) to off (or “O”), or unplug the power supply from the wall for about 15 seconds. Then turn the master power switch to on (or “|”), or reconnect the power cable and boot up and see what happens. By totally removing power, you reset the PSU. It also removes the +5Vsb standby voltage all ATX Form Factor power supplies are required to supply whenever the power supply is plugged into the wall and (if applicable) the master power switch is set to on. This standby voltage is distributed throughout several points on the motherboard, including RAM for faster boots and the USB ports too. This also keeps alive several features, including “wake on keyboard” and “wake on mouse”, and the network interface for “Wake on LAN” commands. A cold reboot ensures any device settings that may be held by the standby voltage are released, then reset when power is restored. A cold reboot also helps ensure any corrupt software settings after installs and upgrades are reset too. Many thanks for the detailed explanation. I didn't think of doing that apart from a normal reboot which didn't help. But again, the question would be as you say above, why a PC AND an Android phone? However, when I got home today, I powered up the PC and I'm dammed if the problem hadn't disappeared! Ditto the phone. I've had problems appear and disappear before without ever getting to the bottom of them. I wonder now if it could have been some problem between me and my ISP. I'll monitor the problem and see what happens but the wife has been happily working away using both devices for hours now and so far, all's good.

Keep us posted. I will and many thanks for the helpful reply. Trevor

Did you try "forget" or removing the network from the devices, and try reconnecting again.

Yes, I did. Many times. However, as I just replied to Bill above, the problem has disappeared - for now at least - with no intervention from me. Thanks for the input.

 

[Bill_Bright]

I've had problems appear and disappear before without ever getting to the bottom of them.

LOL

My background is as an electronics technician supporting air traffic control radio communications systems. We used call mysterious problems that came and went "FM". However, it was not for FM (frequency modulation) radio signals, but rather for a certain type of magic!

I wonder now if it could have been some problem between me and my ISP.

Nah! Well, I cannot speak about "you" but for the most part, your ISP sees everything coming from all your connected devices as coming from just one device with just one IP address - and that one device is your router and the one IP address is the one they assigned to your gateway device (typically the modem).

This could have been some untimely EMI/RFI issue, or maybe "gremlins" (FM) or something more likely such as "operator error". Let's hope the problem stays disappeared.

 

[1freedude]

FM is fucking magic. Or Fucking Motorola.

 

[R-T-B]

If it's 5Ghz, it could be weather radar that shares the same band. It will yield to this, some chipsets more gracefully than others. You obviously can't do much about this.

 

[Bill_Bright]

Nobody needed anyone to explain what FM means. I specifically didn't spell it out just to avoid vulgar, offensive to some, language in a public forum. And please leave Motorola out of this. Regardless any opinion of them, they have been a major player in radio communications (especially mobile radio systems) for the military and emergency response services for decades - and for good reason. They make quality, reliable, innovative products.

If it's 5Ghz, it could be weather radar that shares the same band.

That's true, but the 2.4GHz band is way more crowded. That is one of the primary reasons the 5GHz band was made available for networking devices.

I note things like security cameras, RF mice and keyboards, TV remotes, ceiling fan remotes, many garage door openers, even Bluetooth devices operate in the 2.4GHz band. They may use different protocols than wifi networks, but the band can still be very crowded, especially in densely populated areas. Large apartment complexes, for example, can be very crowded.

LOL I just looked at the remotes sitting on the coffee table in my living room. I have 7 remotes. One for the TV, blu-ray/dvd player, Roku streamer, cable box, space heater, floor fan and A/V receiver. Only one (for the floor fan) uses IR (infrared) light. All the rest operate in the 2.4GHz RF (radio frequency) band.

 

[sacentre]

OP here. Thanks to all for the helpful replies and suggestions on this issue. It looks like the problem was caused by the router! I happened to have an unused, identical unit which I decided to try so I installed this using the saved config file from the old one and the problem has disappeared. At least it hasn't reappeared in over 48 hours.

Obviously, I would have saved everybody a lot of time if I'd thought of trying this sooner and if ALL my other devices connecting to it hadn't been not working normally. It beats me how it could affect just the one PC and Android phone but there we are. I can't think of anything about these two devices that could be the common denominator. So it suggests this was some hardware (or maybe firmware corruption?) issue on the router. I had already tried re-setting the original router to factory defaults but that made no difference.

Anyway, everything is back to normal - at least for now. Thanks again!

 

[de.das.dude]

Ok this is spooky, i just woke up a few hrs back and my tab had the same issue with not being able to see my wifi 5ghz network. it could still see the 2.4 one.

i just restarted the router.

make sure you arent hitting the max connected devices limit

 

[sacentre]

Ok this is spooky, i just woke up a few hrs back and my tab had the same issue with not being able to see my wifi 5ghz network. it could still see the 2.4 one.

i just restarted the router.

make sure you arent hitting the max connected devices limit

Thanks. I never touch settings unless I fully understand what they do. My router hasn't been touched since it was put in apart from the occasional reboot which means I have to re-check my public IP which may have changed (otherwise I can't access my IP camera from the WAN).

Did re-booting your router fix the problem?

 

[de.das.dude]

Thanks. I never touch settings unless I fully understand what they do. My router hasn't been touched since it was put in apart from the occasional reboot which means I have to re-check my public IP which may have changed (otherwise I can't access my IP camera from the WAN).

Did re-booting your router fix the problem?

it did fix the problem.

i think there are too many devices. my parents are visiting and they have 4 devices. plus my smart bulbs, laptop, desktop, handheld, tablet.. my phones... lol.

 

[sacentre]

it did fix the problem.

i think there are too many devices. my parents are visiting and they have 4 devices. plus my smart bulbs, laptop, desktop, handheld, tablet.. my phones... lol.

Yeah, we're all so tied to our digital toys these days and I'm no exception. It's like a drug. The only line in the sand I drew was staying off social media. That's the real cancer in our society.

 

[Bill_Bright]

Obviously, I would have saved everybody a lot of time if I'd thought of trying this sooner

And then we all would have missed a learning opportunity. So this was NOT time wasted.

That said, I still am not buying the first router is "bad". Not when all other devices still worked just fine. You might have an Ethernet port go bad, or an entire wifi band stops working while the other band and Ethernet - wired connections - continue working. But typically, a router either works, or it doesn't.

It just does not make sense for a router to "block" access to 2 devices while allowing access to all others - UNLESS there was a "setting" somewhere configured to block those devices (likely by MAC address). Or perhaps, MAC filtering was enabled where the router was configured only to allow predesignated MAC addresses. It is not actively "blocking" others - it is, in effect, just not "allowing" the others.

Or, another possible router setting involves IP filtering where the router only assigns specific IPs or a limited "range" of IP addresses. This, in effect, limits the number of devices that can be connected at the same time.

You connecting a second router - in effect - reset your network back the router's factory defaults and, I suspect, reset a setting that was blocking (not allowing) those two devices access.

I suspect - though I certainly could be wrong - if you reconnected the first router, reset it back to the factory defaults (your user guide will show how), then configured your network again, it would work just fine.

i think there are too many devices

Nah. In theory, you should be able to connect up to 254 devices. For example 192.168.1.1 thru 192.168.1.255.

I have heard of some WAPs (wireless access points - typically integrated into wireless routers) limiting the number of devices to 30. But even with visitors, that's a lot. And that has no impact on the number of devices connected via Ethernet (wired).

Now if you have several devices all downloading/streaming massive files (videos) at the same time, you certainly can bog down your network by hogging all the bandwidth. This might cause other devices to "appear" to be unable to do anything. But they would still connect.

And of course, not all routers offer the same performance - especially with wireless. And your service agreement with your ISP can sure be a factor too.

they have 4 devices. plus my smart bulbs, laptop, desktop, handheld, tablet.. my phones... lol.

That's not many. Your smart bulbs should not be downloading. Your other devices might be but all at the same time? Not likely.

 

[de.das.dude]

And then we all would have missed a learning opportunity. So this was NOT time wasted.

That said, I still am not buying the first router is "bad". Not when all other devices still worked just fine. You might have an Ethernet port go bad, or an entire wifi band stops working while the other band and Ethernet - wired connections - continue working. But typically, a router either works, or it doesn't.

It just does not make sense for a router to "block" access to 2 devices while allowing access to all others - UNLESS there was a "setting" somewhere configured to block those devices (likely by MAC address). Or perhaps, MAC filtering was enabled where the router was configured only to allow predesignated MAC addresses. It is not actively "blocking" others - it is, in effect, just not "allowing" the others.

Or, another possible router setting involves IP filtering where the router only assigns specific IPs or a limited "range" of IP addresses. This, in effect, limits the number of devices that can be connected at the same time.

You connecting a second router - in effect - reset your network back the router's factory defaults and, I suspect, reset a setting that was blocking (not allowing) those two devices access.

I suspect - though I certainly could be wrong - if you reconnected the first router, reset it back to the factory defaults (your user guide will show how), then configured your network again, it would work just fine.


Nah. In theory, you should be able to connect up to 254 devices. For example 192.168.1.1 thru 192.168.1.255.

I have heard of some WAPs (wireless access points - typically integrated into wireless routers) limiting the number of devices to 30. But even with visitors, that's a lot. And that has no impact on the number of devices connected via Ethernet (wired).

Now if you have several devices all downloading/streaming massive files (videos) at the same time, you certainly can bog down your network by hogging all the bandwidth. This might cause other devices to "appear" to be unable to do anything. But they would still connect.

And of course, not all routers offer the same performance - especially with wireless. And your service agreement with your ISP can sure be a factor too.


That's not many. Your smart bulbs should not be downloading. Your other devices might be but all at the same time? Not likely.

honestly, i wouldnt apply normal knowledge with the router i have

its a no-name branded chinese something that does router duties as well as modem duties (optical input).

it also faces the west, so gets a quite a bit of sunlight hitting it in the latter parts of the day


doesnt even have address reservation! lol.

 

[Bill_Bright]

router duties as well as modem duties

Just for future reference, when the router and modem are integrated into the same device (typically along with a 4-port Ethernet switch and WAP - wireless access point), it is commonly called a "residential gateway". That is yet another often misleading "marketing term". Technically, a residential gateway device is 4 discrete network devices that just happen to share the same main circuit board, case, power supply and menu.

Because these 4 devices are on one board, in the same case and powered by a single power supply, they are much less expensive to manufacturer and distribute and (at least in theory) purchase. The downside of course, is if one portion fails, the entire device must be replaced. This is why I like separates - though my setup is not entirely separate. I have a "wireless router" (integrated router, switch and WAP) and a separate modem.

gets a quite a bit of sunlight hitting it

Never good for any electronics to be in direct sunlight. I recommend you move it or pull down a window shade. You need to block the sun from hitting it directly.