Why is downstream light on Motorola MB8600, blinking periodically?

@EG​ Ok, deleted that picture, thanks for the heads up! Will it now become public?

Yes. Done. TY !

@EG​ There is no amplifier. Only I  thing I know of, after the pedestal, is that filter they install, inside that box, by the ground block, that I think is in case you get TV, forget what it's called......MOCA filter??

@EG​ I'm referring to the filter that Xfinity installs right at

the ground block, isn't that called a MOCA filter, or something like that?

@EG​ Ah ok, gotcha. Thanks for that, I simply didn't know. Mine has gone a few days without the DS light blinking, so time will tell. I doubt my power levels are causing that though, because they've always been in that range, and this blinking light thing is new. That said, what's your opinion on a forward path attenuator at the modem? It's been suggested to me several times, and a few people have called it a bandaid for a larger problem. I just don't know if my power levels are off enough to warrant Xfinity making a service call,

@EG​ Yeah, when it starts blinking, nothing seems different. Not that I can notice, that's for sure. I will try the attenuator, just for fun. Besides, Xfinity isn't going to be too concerned about my power levels anyway, correct? They're borderline too high, my understanding.

If you did have a tech come out, they too may install an attenuator pad.

@EG​ Ah ok. Yeah, no need for that, I'll give it a try.

Awesome! Thank you for the update. Our team will circle back in a week just to make sure things are solid. 

@acillatem​ 

Fingers crossed !!!

I would be asking the same questions! In my experience the most common thing that might lead to that type of flutter is some temporary ingress. That is just some type of outside noise causing a light attenuation, overall the signal level and the flutter you experienced I feel are most likely not related. 

@EG and @XfinityThomasB 

Switched from the Connect more/200mbps plan, to Fast/400mbps, and the modem rebooted, and speed tests showed only slightly faster than before. With Connect more, I almost always got around 240mbps, with advertised speed being 200mbps. The support chat person asked me if I had reset the modem after the reboot, after I had confirmed the new plan. I had not, so I did. Nothing changed. Then he comes back and tells me my downstream power levels are low, which they have been ever since I got Xfinity.....screenshots attached. But anyway, my opinion is, nothing changed drastically from switching from one plan to another.

Then the agent said he would send a provisioning signal to the modem, to give it the right information, because maybe it was just a hiccup with their system, but that didn't do it.

So then, FWIW, I put a 6db attentuator on the back of my modem, and power levels are much better, but speeds haven't changed. Still getting just slightly faster speeds than with the Connect More/200.

Screenshots are AFTER the 6db attenuator was put on the back of my modem. I just can't see how this can be at my end, when everything was fine with the old plan, even with the lower power levels.

Any ideas? Thanks!

Ok, so I just tested it straight from the modem, and I'm getting the correct speeds, so something with my router is causing the issue, even though with my previous plan, I got the correct speeds, going through the same router. Not sure the solution, but it's not Xfinity. If I can't resolve this with a new router or whatever, then I will be switching back to Connect More, as it didn't have this issue with that plan, for some weird reason.

Can I simply resolve this with a better, newer router?? And this is hardwired to the router, but something is affecting the speeds.

Netgear WNDR4300....probably 10 years old. Upon digging around very little, sounds like it just can't handle the new speeds. Easy fix, and good excuse to upgrade to Wifi 6 and all that.

Did you try any of those things ?

@EG​ It's a Netgear WNDR4300. I just tried another port, swapped out the ethernet cable going from the modem to the router, and unchecked the two boxes shown, from QoS in the screenshot. Maybe a few mbps faster, but nothing significant, still under 300mbps, and it's like 475 straight from the modem.

@EG And also, here are the 'statistics' from the internet port tab, in the router, if that means anything. I think it's just an old router that can't handle it, but I don't know.

@EG​ Yeah, that's what I was thinking, but worth trying your suggestions. It wigged out on me the other day anyway, and now a lot of them are Wifi6, as well as just better range, among other things, so yeah, time to get with the times, lol.

@EG Do you have any preferences, as far as brand? I've always thought Netgear and Linksys, but ASUS was recommended to me today. It's just me and my wife, no gaming, but I just want somethng reliable, good range, and can handle my new speeds, which isn't much to ask.

@EG​ Ok thanks! I can appreciate not recommending brands too. I think at the end of the day, they're all relatively the same, and even something with great reviews can fail, and vice versa. It can make your head spin, and I have OCD, so.........