Question Modem randomly shutting down and restarting

[ReemiReemo]

I'm pretty lost here, It's been a week since I've had internet issues and have had a technician come over 3 times now, I find that modem will randomly start shutting off and restarting, I've tested it on 2 different wall outlets and it still randomly shuts down after about 30 mins or so and then starts back up. There are apparently no issues in my area according to my ISP so it's not that.

It's strange because yesterday before we replaced the modem it actually worked for the entire day without much issue and just this morning it's at it again despite the entire modem being replaced.

I also had the modem itself replaced today so it's brand new. I don't even know what it could be anymore and would really appreciate some help. I'm at my wits end here as I have no clue how these things work, please let me know if I missed any crucial information.

 

[bill001g]

Note I will assume you have a cable modem if not none of the below likely applies.

It all depends on where the tech tested from. They commonly check where the cable enters the house.

If you have poor cabling or maybe too many splitters the problem could be the extra cable in your house.

I would check the logs in the modem and see if it tells you why it is rebooting. It is not likely something like a power issue if a second unit, and assuming new power block, also fails.

Almost all modems have some screen that will show you the power levels. This is kinda what the tech was looking at with his meter. There are table that tell you the recommended values. The exact values vary a bit based on the type of docsis and I am not going to cut and paste those tables here.

If the signal levels are out of the recommended range it would be common for the modem to reboot. I would if possible move the modem to where the cable comes into the house and check the signal levels. It all depends on how long you would need to leave it connected here to see if the reboot does not happen.

Fixing the wires and splitters inside your house can be tedious project. Generally why a ISP solution is to drill a new access directly though a outside wall to the room with the modem.

 

[ReemiReemo]

Note I will assume you have a cable modem if not none of the below likely applies.

It all depends on where the tech tested from. They commonly check where the cable enters the house.

If you have poor cabling or maybe too many splitters the problem could be the extra cable in your house.

I would check the logs in the modem and see if it tells you why it is rebooting. It is not likely something like a power issue if a second unit, and assuming new power block, also fails.

Almost all modems have some screen that will show you the power levels. This is kinda what the tech was looking at with his meter. There are table that tell you the recommended values. The exact values vary a bit based on the type of docsis and I am not going to cut and paste those tables here.

If the signal levels are out of the recommended range it would be common for the modem to reboot. I would if possible move the modem to where the cable comes into the house and check the signal levels. It all depends on how long you would need to leave it connected here to see if the reboot does not happen.

Fixing the wires and splitters inside your house can be tedious project. Generally why a ISP solution is to drill a new access directly though a outside wall to the room with the modem.

I don't think there are any splitters on my cable but I do wanna add while inspecting the router earlier I think the tech may have given me the wrong power adapter for my router, the router demands 12v and 2amps but the power adapter they gave me only outputs 12v and 1amps. My previous router had a 12v and 2amp power adapter and had totally different issues for this new one.

My previous one would just lose internet service while the new one shuts down totally, and I also noticed the power adapter heats up much hotter than before. Is that a possible cause? and is there any explanation as to why it would allow it to run for 30mins to an hour despite having a lower output.

Sorry all new to this.

 

[bill001g]

It all depends on how much power the modem really uses many times they do not actually use the full rated power.
Since you had issues on another modem it is not likely the power supply.

 

[ReemiReemo]

It all depends on how much power the modem really uses many times they do not actually use the full rated power.
Since you had issues on another modem it is not likely the power supply.

Speaking of that after observing it more they have totally different issues, the previous one would just lose service but not shutdown while this one does, both of have them totally different power supplies. I'm not really sure just throwing out more info incase it helps.

 

[bill001g]

Could be the power then. Could be the voltage or something is dropping too low and causes a reboot.

It is not uncommon though for the modem to reboot itself if it loses the signal. It pretty much looks the same as if you have unplugged and plugged it back in. Key here is there are generally entries in the log where you see some kind of errors right before it reboots. Power would just be pretty much normal logs showing lots of reboots.

 

[ReemiReemo]

Could be the power then. Could be the voltage or something is dropping too low and causes a reboot.

It is not uncommon though for the modem to reboot itself if it loses the signal. It pretty much looks the same as if you have unplugged and plugged it back in. Key here is there are generally entries in the log where you see some kind of errors right before it reboots. Power would just be pretty much normal logs showing lots of reboots.

Unfortunately I could not find any logs of the sort in my router settings? (assuming it's the website where you enter the IP looking string of codes) Unless I'm not looking hard enough. it's mostly just settings I can change

 

[bill001g]

It varies a lot between brands of modems. A very common ip they use is 192.168.100.1

You will generally see some common things like T3 timeouts etc. All modems seem to get some it is when you get a lot in a short period of time. Generally when the device reboots itself you see some startup messages.

 

[ReemiReemo]

It varies a lot between brands of modems. A very common ip they use is 192.168.100.1

You will generally see some common things like T3 timeouts etc. All modems seem to get some it is when you get a lot in a short period of time. Generally when the device reboots itself you see some startup messages.

Gotcha I'll look into it more and still test out my power adapter theory just incase that was the issue, thanks for the help and info genuinely appreciated!